A PERSPECTIVE ON THE ECONOMIC TORTS

Author(s): Lee Eng Beng

Source: Singapore Journal of Legal Studies, (December 1996), pp. 482-523
Published by: National University of Singapore (Faculty of Law)
Stable URL: https://www.jstor.org/stable/24866903
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Singapore Journal of Legal Studies
[1996] 482 - 523

A PERSPECTIVE ON THE ECONOMIC TORTS

A unifying principle underlying the economic torts - interference with contract, conspir
intimidation and unlawful interference with trade or business - has yet to be authoritati
recognised by the courts. For this reason, the development of the underlying legal
policy bases of liability and non-liability with respect to these torts has been hinde
to a considerable extent. The current boundaries of their operation are conseque
also unduly restricted, and they co-exist somewhat uncomfortably with analogous a
overlapping principles of liability in other areas of the law, principally equity.
article offers some suggestions as to the rationalisation and resolution of some of t
issues and attempts to map what, in the writer's view, is the best way forward
particular, it is submitted that a general principle of liability for intentionally-infli
non-physical harm, subject to a sufficiently wide and pliable defence of justifica
should be recognised by the common law.

I. Introduction

RECENTLY, one of the most frequently accepted and reiterated pr

sitions in relation to the economic torts is, rather unfortunately, that t
are in complete disorder.1 It is difficult to disagree with this. While det
rules have evolved with regard to each of the economic torts,2 tha
interference with contract, intimidation, conspiracy and unlawful inte
ference with trade or business, the same cannot be said with respec
the founding of a logical structure for the area as a whole. Still les
there been any judicial consideration of the relationship between these t

They are in a mess and are of ramshackle construction: see Wedderburn, Rocking The T
(1983) 46 MLR 224 at 226; Carty, Intentional Violation of Economic Interests: The Li
of Common Law Liability (1988) 104 LQR 250 at 250 and 278; Eekelaar, The Conspir
Tangle (1990) 106 LQR 223 at 223. See also Clerk & Litidsell on Torts (17th Ed, 1
at para 23-01.
These are comprehensively and lucidly treated in many of the leading tort texts: Clerk
Lindsell on Torts, supra, note 1, Ch 23; Rogers, Winfield and Jolowicz on Tort (13th
1989), Ch 18; Fleming, The Law Of Torts (18th Ed, 1992) at 689-709; Salmond & Heus
on the Law of Torts (20th Ed, 1992), Ch 16; Brazier, Street On Torts (9th Ed, 1993)
7; Markesinis & Deakin, Tort Law (3rd Ed, 1994) at 375-397 and 401-2. For the Austr
perspective, see Trindade & Cane, The Law of Torts in Australia (2nd Ed, 1993) at 2
236 and Balkin & Davis, Law of Torts (1991), Chs 21 and 22. Fleydon, Economic T
(2nd Ed, 1978) is an excellent specialist text on the economic torts.

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SJLS A Perspective on the Economic Torts 483

and the incidence of liability in analogous situations

law.

It is tempting to conclude that the economic torts

disparate miscellany which are usually grouped t
convenience or neatness. Indeed, such a conclusion is
on the existing state of the authorities. The
compartmentalised approach, however, ignores the
of policy concerns underlying the purpose and oper
torts, which are admittedly sometimes obscured by i
lous rules. The factual similarities in the contexts in
invoked are also too obvious to brush away. On the ot
and modify the existing rules so as to fit them into
is a daunting task which will take many years and m
to try to accomplish. What this article hopes to achie
a starting point for such reform, that is, the organi
torts under a single and coherent principle of causin
injury to another person without lawful cause or justifi
between the economic torts and other instances of
intentionally-inflicted economic loss will also be

II. Founding Concepts

1. Bases of liability

It hardly needs to be pointed out that tort law does not accord to economic
interests the same level of protection as it extends to property rights and
bodily integrity. It is well-entrenched law that recovery for pure economic
loss is ordinarily denied by the law of negligence.3 This is chiefly attributable
to three risks: the escalation of the incidence and quantum of liability,
disproportion between the fault of the defendant and the extent of his
liability, and the use of tort law to outflank the limitations of contract
law, in particular the doctrine of privity. None of these considerations
apply with any significant force in cases of deliberately-inflicted damage
to economic interests. There would be no risk of a wide field of plaintiffs

3 The existence of special circumstances such as a relationship of reliance, a voluntary

assumption of responsibility or some other specific relationship must be shown before there
can be such recovery. No liability attaches for negligent infringement of economic rights
in the absence of such factors: Cattle v Stockton Waterworks Co (1875) LR 10 QB 453;
Weller v Foot & Mouth Disease Research Institute [1966] 1 QB 569; Spartan Steel and
Alloys Ltdv Martin & Co (Contractors) Ltd[l913] 1 QB 27 .CandlewoodNavigation Corporation
Ltd v Mitsui OSK Lines Ltd [1986] AC 1; Leigh & Sillavan Ltd v Aliakmon Shipping Co
[1986] AC 785. Cf Nicholls v Township of Richmond (1983) 145 DLR (3d) 362.

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484 Singapore Journal of Legal Studies [1996]

in the economic torts if the plaintiff must in some sens

aimed at by the defendant.4 The evident blameworth
who has intentionally injured another person's int
that he does not attract or deserve much sympathy.
of contract is traditionally concerned with compensa
is a mechanism which is neither appropriate nor freque
against intentionally-inflicted financial loss.
Yet, it remains the law that a person's intentional co
the economic interests of another will not found liabi
this is because, unlike the law of negligence which is
allocation, the economic torts are concerned with sti
permissible economic behaviour.5 The need to preser
and maintain a competitive market means that there
all intentionally-inflicted economic loss. Everyone ha
his own business upon his own lines and as suits h
the result may be that he interferes with other people
Conversely, the right to pursue one's trade is qualifi
of others to do the same and compete with him, tho
Clearly, this rationale does not support the full wid
that intentional injury to economic interests will not f
There must be limits to the principle that a person i
he likes to further his trade interests, and these are
interest in maintaining a level playing field in the real
Two of the most obvious restrictions are, firstly
unlawful conduct and, secondly, he cannot violate
right. It is thus not surprising that the bases of liab
torts have traditionally been founded on the prese
these factors.
A possible third basis of liability is one which requires the court to balance
the respective economic and moral claims of the parties. This is a task which
the courts have on many occasions shunned; indeed, in the context of the
economic torts, it has been said that to draw a line between fair and unfair
competition passes the power of the courts.8 On closer examination, however,

Heydon, supra, note 2, at 9. See also Hepple & Matthews, Tort: Cases And Materials (4th
Ed, 1991), at 673.
Carty, supra, note 1, at 277.
Lord Dunedin in Sorrell v Smith [1925] AC 700 at 718; Lord Pearce in Rookes v Barnard
[1964] AC 1129 at 1233.
Lord Davey in Allen v Flood [1898] AC 1 at 173.
Fry LJ in Mogul SS Co v McGregor, Gow & Co (1889) 23 QBD 598 at 625-626, approved
by Lord Bramwell on appeal [1892] AC 25 at 49.

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SJLS A Perspective on the Economic Torts 485

this is hardly a convincing reason. In certain situation

deemed it proper to undertake the task of deciding w
is fair, the prime example being the determination of the
of trade clauses.9 It cannot be said that the need for s
less in the context of intentionally-caused economic h
such a task is in fact undertaken in the context of the
albeit in a more restricted sense, when the application
justification has to be considered.

2. Landmark decisions

Consideration must start with the House of Lords' decision in Mogul

SS Co v McGregor, Gow & Co10 which established the uncontroversial
proposition that it is not tortious for a group of traders to form a cartel
for the purpose of advancing their own trade interests though it may
incidentally injure the business of rival traders, provided that no unlawful
means are used. It was in the Court of Appeal, however, that Bowen LJ
formulated a general principle that it was a tort to intentionally engage in
conduct which was calculated in the ordinary course of events to damage
and which in fact damaged another person's property or trade, unless such
acts were done with just cause or excuse."
In Allen v Flood,12 the House of Lords applied the principle established
by the Mogul decision to competition in labour. The defendant, acting as
the representative of Group X employees, told the employer that Group
X employees would quit unless the employer terminated the employment
of Group Y employees, the plaintiffs. The employer discharged the plaintiffs
accordingly. It was found by the jury that the defendant had maliciously
caused the employer to discharge the plaintiffs, that is, the defendant had
injured the plaintiff out of spite and ill-will and not for securing any
advantage to himself. The House of Lords held, however, that the presence
of malice did not take the case out of the ambit of the Mogul decision.
Despite the lengthy speeches delivered, this was all that was decided:13 the
fact that the defendant acts maliciously does not render a tort what is

Heydon, supra, note 2, at 27.

[1892] AC 25.
(1889) 23 QBD 598 at 613-614. See also Skinner & Co v Shew & Co [1893] 1 Ch 413
at 422.

Supra, note 7.
Lord Macnaghten, Quinn v Leathern [ 1901 ] AC 495 at 508 ; Brisbane Shipwrights Provident
Union v Heggie (1906) 3 CLR 686 at 695. See also Dicey (1902) 18 LQR 1.

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486 Singapore Journal of Legal Studies [1996]

otherwise not a tort.14 The general principle of liabili

LJ earlier was accordingly rejected.15
In the third House of Lords' decision in the series,
there was apparently a withdrawal from the position
In Quinn v Leathern, the defendants were union mem
with the plaintiff employer over his employment of
After the plaintiff refused to discharge the non-
defendants forced the plaintiffs main customer to c
plaintiff by threatening the customer that otherwis
his employees. It was found that the defendants had
ill-will as opposed to protection of their self-interes
defendants were found liable for conspiracy, althoug
had been used. The rule in Allen v Flood that the pre
never make tortious an otherwise lawful act was thus shown not to be
unqualified. The extent of the qualification on Allen v Flood, however, was
not made clear by the speeches delivered. In particular, it was not clear
whether their Lordships were deciding that the exception to Allen v Flood
applied only in cases of malicious acts by a combination of persons or
whether some broader qualification had been intended. One view which
has been expressed subsequently is that the element of conspiracy was the
'very gist and substance' of the decision in Quinn v Leathern and that it
would be the 'leading heresy' to suggest otherwise.17 On the other hand,
there have been statements of equal authority to the contrary.18 The
controversy has yet to be laid to rest. As Lord Devlin remarked more than
60 years after Quinn v Leathern was decided, he was not at all sure that
it could be said even then with certainty what it decided.19 It could thus
be plausibly argued that, despite Allen v Flood, the principle of liability

See also Stevenson v Newnham (1853) 13 CB 297 and Bradford v Pickles [1895] AC 597.
This principle has been accepted in Singapore: Haron bin Mundir v Singapore Amateur
Athletic Association [1992] 1 SLR 18 at 31-32, affirmed [1994] 1 SLR 47.
See especially Lord Herschell, supra, note 7, at 138-9. But see how Lord Herschell's
disapproval was treated in Brisbane Shipwrights Provident Union v Heggie, supra, note
13, at 695-696.
Supra, note 13.
Lord Dunedin, Sorrell v Smith, supra, note 6, at 719-720. See also Lord Porter, Crofter
Hand-Woven Harris Tweed Co Ltd v Veitch [ 1942] AC 435 at 487. Lord Dunedin's statement
was recently endorsed in Ontario in the decision of Daishowa Inc v Friends of the Lubicon
(Ontario Court of Appeal, unreported, 23 January 1996).
Lord Loreburn Viscount Cave LC (with whom Lord Atkin concurred) and Lord Sumner,
supra, note 6, at 713 and 739 respectively. See also Lord Lindley, Quinn v Leathern, supra,
at 537; Stirling LJ, Giblan v National Amalgamated Labourers' Union Of Great Britain
And Ireland [1903] 2 KB at 623; Hodges J, Bond v Morris [1912] VLR 351 at 360.
Lord Devlin in Rookes v Barnard, supra, note 6, at 1215-1218, especially at 1216.

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SJLS A Perspective on the Economic Torts 487

established in Quinn v Leathern may extend to maliciou

individual.

It is significant to note that Allen v Flood has been rejected by the

American courts, which have instead adopted Bowen LJ's general principle
of liability for intentional harm caused without just cause or excuse.20 This
is now known in America as the prima facie tort doctrine.21 Under this
doctrine, for example, a wealthy defendant who set up a rival hairdressirig
business and under-cut the rates of the plaintiff barber for the sole purpose
of driving him out of business would be liable.22
The position in Australia is less certain. Early this century, there was
some disapproval of Allen v FloodP In Brisbane Shipwrights' Provident
Union v Heggie,24 the Australian version of Quinn v Leathern, the High
Court of Australia heavily qualified Allen v Flood. The material facts in
Brisbane Shipwrights were virtually identical to those in Quinn v Leathern,
and the court came to the same ultimate conclusion that the defendants
were liable. However, in contrast to the diversity of approaches seen in
Quinn v Leathern, the High Court adopted, with qualifications, Bowen LJ's
formulation of the general principle of liability. Griffith CJ, delivering the
judgment of the Court, laid down the basic rule that any interference with
the rights of another, including the right to trade and seek employment,
which in fact occasions damage to him is actionable, unless the interference
is authorised, justified or excused by law.25 However, interference which
results merely from the exercise of free competition in trade, such as the
acts in the Mogul case and Allen v Flood, or from the exercise of a right
of property,26 is not actionable. This is because these are rights given by
law.27 Other types of interferences, which are neither authorised by law
nor expressly forbidden by law, are prima facie neutral and, therefore,

See Aikens v Wisconsin 195 US 194 at 204.

However, it appears that this doctrine is seldom invoked in America. For further discussion,
see Heydon, Economic Torts (2nd Ed, 1978) at 28 and 128-129.
Tuttle v Buck (1909) 107 Minn 145, 119 NW 946.
Madden CJ thought that it should be overruled: Marte II v Victorian Coal Miners ' Association
(1903) 29 VLR 475 at 508. In Bond v Morris, supra, note 18, Allen v Flood was followed
but on the basis that the defendant in that case (ie, Allen v Flood) did not act maliciously.
Supra, note 13.
Supra, note 13, at 697-698 (proposition I).
The example given was Bradford v Pickles, supra, note 14: see supra, note 13, at 700.
In Bradford, the House of Lords held that a defendant who maliciously abstracted percolating
underground water from his land for the purpose of preventing the water from reaching
the plaintiffs land, so as to make it necessary for the plaintiff to purchase his land at a
high price, was not liable as he was lawfully exercising a right of his property.
Supra, note 13, at 698 (proposition II) and 700.

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488 Singapore Journal of Legal Studies [1996]

justified or excused, unless the victim can show that

deliberate and the defendant was actuated by a desir
On the other hand, if the interference is a direct resu
the cause of action is complete as soon as there is act
principles were declared by the High Court to be
authority, including Allen v Flood.
Surprisingly, Brisbane Shipwrights has been la
though it is a decision of the High Court. It has
in subsequent decisions.30 Indeed, the leading Austra
the adoption of a general principle of liability fo
economic harm free from the constraints imposed by
referring to the fact that much of the work was done b
90 years ago. Subsequent decisions of the High Co
appeared, however, to be unwilling to adopt the posi
Shipwrights. In McKernan v Fraser?2 Evatt J expressly
authorities did not support the proposition that all wi
unless justified or excused, although he recognise
proposition. A similar view appeared to be favour
in James v Commonwealth,33 Significantly, Brisban
cited in either case. The conclusion, then, is that the
probably even more so than in England, remains
More recent judicial discussion on the effect of All
non-existent. The law has developed by way of distin
Further, though the full width of the principle in A
truth have been significantly restricted, it is freque
courts to be good law. Quinn v Leathern has been

Supra, note 13, at 699 (propositions III, IV and V).

Supra, note 13, at 700. This proposition requires qualification
sufficient intent in the light of Northern Territory of Australi
1, but otherwise does not affect the present discussion.
Brisbane Shipwrights was referred to as authority for a gener
intentional harm by the Northern Territory Court of Appeal in Nor
v Mengel (1994) 95 NTR 8 but this decision was subsequently r
see ( 1995) 129 ALR I. The High Court did not mention Brisbane Sh
established therein. Apart from this, Brisbane Shipwrights has b
propositions in a handful of cases: see, eg. Hay v The Austral
Engineers ( 1906) 3 CLR 1002 at 1010; Transport Workers Union o
(1980) 28 ALR 589\Ansett Transport Industries (Operations) Pty
of Air Pilots [1991] VR 637.
Balkin & Davis, supra, note 2, at 670; Trindade & Cane, sup
(1931) 46 CLR 343 at 380-381.
(1939) 62 CLR 339 at 362-366.
See Rogers, supra, note 2, at 495.

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SJLS A Perspective on the Economic Torts 489

as merely introducing an anomalous exception in th

malicious action by a combination of persons, that is, t
by lawful means. Thus it has been remarked that the
by lawful means is anomalous because its effect is
not actionable by one person becomes actionable when
two or more persons pursuant to an agreement.33 Conse
framework for the economic torts that has developed
the assumption that the motive of the defendant is ir
conspiracy by lawful means, in determining wheth
tentionally causing injury to the plaintiff's economic
cases, liability could be imposed only where a legal rig
has been interfered, as in the case of interference with
the defendant has utilised unlawful means to cause inj
as in intimidation, unlawful conspiracy and unlawful in
or business. The law has thus adopted formal as opp
criteria for identifying illegitimate or unfair competit
This, however, must not obscure the fact that, until the
and authoritatively addressed, the principle establishe
is not beyond challenge.

3. A suggested formulation

It is submitted that much of the reasoning in Brisb

may be adopted as the analytical framework for a general
in respect of intentionally-caused economic loss. This
The general rule is that any intentional interference with
(including what should strictly be termed as economic
causes loss to him is actionable, unless the interference i
or excused by law. Where unlawful means have been u
is possible. On the other hand, in situations where a de
an undoubted legal right, as opposed to merely exer
do a neutral act, the defendant is never liable or,
justification always applies. In a case where the defend
act, the availability of justification depends on wheth
a desire to injure the plaintiff.
It is felt that one significant qualification is necessa
Shipwrights formulation the scope of justification is

35 Lord Diplock, Lonrho Ltd v Shell Petroleum Co Ltd (No 2) [1

Bridge, Lonrho pic v Fayed [1992] AC 448 at 307-309. See also
she then was) in X Pte Ltd v CDE [1992] 2 SLR 996.
36 Markesinis & Deakin, supra, note 2, at 378.

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490 Singapore Journal of Legal Studies [ 1996]

strictly defined by reference to the presence of unla

intent. This tends to create a relatively inflexible c
to deal with the innumerable ways in which intent
harm may be inflicted. As will be suggested later
down that conduct involving unlawful means or mal
be justified. Further, the concept of justification s
the fact whether there has been a violation of the
or merely an interference with his economic expect
earlier, whether the defendant's conduct passes the
competition.
The resulting analytical framework is as follows, fhe starting point
would, again, be the all-important principle enunciated by Bowen LJ: all
intentionally-inflicted economic harm is actionable unless lawful cause or
justification is shown. Where the defendant is acting pursuant to a positive
legal right as opposed to exercising his liberty to do a neutral act, as in
Allen v Flood and the Mogul decision, justification will always apply. In
other cases, whether justification applies would depend substantially on the
presence of at least three factors: the violation of a legal right as opposed
to a mere expectation, the use of unlawful means and malicious conduct
on the part of the defendant. In exceptional cases, there may be a residual
fourth factor of reprehensible conduct which, although aimed at advancing
the doer's interests rather than injuring any person, transgresses the bound
aries of what is generally accepted by reasonable commercial men as fair
competition. It should be remembered that these factors, of course, carry
varying degrees of weight in different situations in relation to the imposition
of liability. If none of the factors are present, justification will apply.
However, if one or more of them are present, then all the relevant cir
cumstances of each individual case will have to be considered in ascertaining
whether the defendant's conduct should nevertheless be justified.
Admittedly, this formulation requires the drawing of a possibly difficult
distinction between a positive legal right and a mere liberty; it could be
argued that, whatever the law does not forbid, one has the right to do.37
The force of this argument is much reduced, however, when one appreciates
that the right-liberty distinction is not an absolute one. The real underlying
question is whether the right claimed by the defendant as justifying his
particular action is, as a matter of policy and the public interest, so revered
that no limits may be placed upon its manner of exercise, not even the
lowest form of restriction that he cannot abuse the right to maliciously injure
others. A second argument against the suggested formulation would be the

37 See, eg, Megarry VC in Malone v Metropolitan Police Commissioner [1979] 2 WLR 700
at 720 and Abdullah v Regina [1954] MLJ 195 at 196.

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SJLS A Perspective on the Economic Torts 491

prospect of over-extensive liability, but again this is unc

extension made to the present state of the law is that har
maliciously or by commercially reprehensible conduc
businessmen would term unfair would be actionable, no
no unlawful means have been employed. Maliciousnes
encountered nor easily proved, while the concept of
rehensible conduct sets a sufficiently high threshold to ens
only behaviour which is, according to minimum standa
morality, manifestly unfair. Finally, it may be said, wit
the formulation would introduce an excessively wide ju
the operation of which would create uncertainty. The an
any such uncertainty, if it exists, would not be very d
encountered in the context of the existing justificat
specific economic torts. In any event, uncertainty in th
law is probably inevitable; where legal rules have to
wide field of activity, vagueness in the formulation of th
to the court's sense of justice and common sense simply
It is submitted that the suggested formulation strike
between free trade and competition on the one hand an
economic interests against intentional harm on the oth
protection to economic interests but yet addresses the co
should not unduly fetter freedom of trade and competit
be seen, the authorities may be gradually moving to such
in a frustratingly uncoordinated and piecemeal manner
the formulation would also provide a much-needed theo
which to organise the existing authorities, map the way f
the relationship between the economic torts and similar p
in other areas of the law. Most importantly, it would m
more capable of handling bad behaviour and abuse of ri
much more flexible and much more based on factors of substance rather
than technicality.38
Consideration will now be made of each of the economic torts - in
terference with contract, intimidation, conspiracy, unlawful interference with
trade or business - to determine if and how far the present state of the
law is consistent with the above principles.

38 Heydon, supra, note 2, at 129.

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492 Singapore Journal of Legal Studies [1996]

III. INTERFERENCE WITH CONTRACT

1. General principles

According to the original formulation of this tort in the leading case

of Lumley v Gye,39 if a defendant, without lawful justification, knowingly
procures or induces a party to a contract to breach his contract with the
plaintiff to the damage of the plaintiff, he is liable to the plaintiff for the
resulting loss. There must be some act by the defendant which is capable
in law of amounting to interference. Any active step taken by a defendant,
having knowledge of a covenant, by which he facilitates a breach of that
covenant is enough, such as when he takes a transfer of property which
he knows is offered to him in breach of covenant.40 On the other hand,
no liability ensues if there is no sufficient act of interference, even if the
value of the plaintiffs contractual rights are reduced by the defendant's
acts.41 It is also not enough to merely facilitate the commission of the act
of interference.42
The defendant's conduct need not be aimed at the plaintiff and there
need not be a desire to injure him;43 malice in the sense of spite or ill
will is not required.44 It is enough that the defendant knows of the existence
of the contract and intends to procure the interference with its perfor
mance.45 It has been held that the fact that the defendant knew that interference
with the plaintiff's contract was an unavoidable by-product of his conduct

Lumley v Gye (1853) 2 E&B 216. The principle has since then been repeatedly approved
by the House of Lords: see, eg, Quinn v Leathern, supra, note 13; South Wales Miners'
Federation v Glamorgan Coal Co Ltd [1905] AC 239; Jasperson v Dominion Tobacco Co
[1923] AC 709; JT Stratford & Son Ltd v Lindley [1965] AC 269; Merkur Island Shipping
Corporation v Laughton [1983] 2 AC 570. The principle has also been accepted by the
Malaysian Federal Court: Loh Holdings Sdn Bhd v Peglin Developments Sdn Bhd [ 1984]
2 MLJ 105. See also Mok Tai Dwan v Kelang Pembena Kereta-Kereta Sdn Bhd [1996]
1 MLJ 586. Note, in the context of trade disputes, s 10 of the Trade Disputes Act (Cap
331).
British Motor Trade Association v Salvadori [1949] Ch 556; Rickless v United Artists
Corporation [1988] QB 40; Law Debenture Trust Corp v Ural Caspian Oil Corp Ltd [1993]
1 WLR 138. Cf Batts Combe Quarry Ltd v Ford [1942] 2 All ER 639.
RCA v Pollard [1983] 1 Ch 135.
CBS Songs Ltd v Amstrad Consumer Electronics pic [1988] 1 AC 1013 at 1058.
Stuart-Smith LJ in Edwin Hill & Partners v First National Finance Corporation pic [1989]
1 WLR 225 at 234.
South Wales Miners' Federation v Glamorgan Coal Co Ltd, supra, note 39, at 246 and
250; Greig v Insole [1978] 1 WLR 302 at 332; Pritchard v Briggs [1980] 1 Ch 338 at 410.
Merkur Island Shipping Corporation v Laughton, supra, note 39, at 607-608. The defendant
need not know of the precise terms of the contract: Emerald Construction Co Ltd v Lowthian
[1966] 1 WLR 691; Greig v Insole, supra, note 45, at 335-6. See also Smith v Morrison
[ 1974] 1 WLR 659 and Pritchard v Briggs, supra, note 44, at 413-414. CfNicholls v Township

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SJLS A Perspective on the Economic Torts 493

is probably not enough, if he was not actually targ

interests.46 More recently, this view has been doubted,
that the requisite intention may be present where the
injury to the plaintiffs contract rights was a probable
action.47

2. Direct and indirect interference

It is usually said that the act of interference may be direct or indirect.

The significance is that, in the case of indirect interference, there is the
additional requirement that the means used must be unlawful.48 A clear case
of direct interference would be the defendant's persuasion or inducement
of the contract-breaker,49 but in other cases it is much more difficult to
determine this question. In spite of attempts to draw a distinction between
direct and indirect interference,50 it is plain that the distinction is not wholly
clear.51 A second difficulty with the direct-indirect distinction is the absence
of a satisfactory basis for having, in cases of indirect interference but not
in cases of direct interference, the additional requirement of unlawful means.
The suggested rationale for such requirement is that liability in cases of
indirect interference must be somehow circumscribed,52 but it is difficult
to accept that 'liability depends on a possibly trivial breach of the law which
is of no concern to the plaintiff .53 Whether an act of interference is direct

of Richmond (1983) 145 DLR (3d) 362 where the Court recognised the existence of a tort
of negligently inducing a breach of contract. Such a proposition has, on the other hand,
been disclaimed by the Hong Kong Court of Appeal in Club Deluxe Ltd v Club Metropolitan
Ltd [1995] 2 HKLR 69 at 78.
Barrets and Baird (Wholesale) Ltd v Institute of Professional Civil Servants [1987] IRLR
3. C/the county court decision in Falconer v ASLEF [1986] IRLR 331.
Millar v Bassey, The Independent, 26 August 1993.
Torquay Hotel Co Ltd v Cousins [1969] 2 Ch 106 at 138; Wolley v Dunford (1972) 3 SASR
243 at 267; Davies v Nyland (1975) 10 SASR 76 at 98; Greig v Insole, supra, note 44,
at 332; Merkur Island Shipping Corporation v Laughton, supra, note 39; Loh Holdings Sdn
Bhd v Peglin Development Sdn Bhd, supra, note 39; Boral Bricks NSW Pty Ltd v Frost
(1987) Aust Torts Reports 80-097; Mok Tai Dwan v Kelang Pembena Kereta-Kereta Sdn
Bhd, supra, note 39. See also F Bowles & Sons Ltd v Lindley [1965] 1 Lloyd's Rep 207
at 212.

Lord Esher MR and Jenkins LJ, DC Thomson & Co Ltd v Deakin [1952] Ch 646 at 681
and 694 respectively; Speight J, Pete's Towing Services Ltd v Northern Industrial Union
[1970] NZLR 32 at 47.
See, eg, the formulation in Greig v Insole, supra, note 44, at 334.
Davies v Nyland, supra, note 48, at 99.
See Lord Denning MR in Torquay Hotel Co Ltd v Cousins, supra, note 48, at 138.
Heydon, Interference With Contractual Relations: Recent Developments, in Simos (ed),
Negligence and Economic Torts (1980) at 144. See also Lord Radcliffe in JT Stratford &
Son Ltd v Lindley, supra, note 39, at 330 and Rogers, supra, note 2, at 501-502.

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494 Singapore Journal of Legal Studies [1996]

or indirect is principally a question of causation, and

how the presence of unlawful means overcomes the ab
nexus. If anything, it should be the intention of t
compensates for the lack of causal proximity.
It has been suggested that liability in cases of indirect
be regarded as a particular example of the tort of unl
with trade or business.54 This approach, however, w
retention of the problematic distinction between d
terference. The better view is to treat the matter simp
and causal proximity.55 Taking into account the defen
the causal proximity between his act and the plaintiff s in
interference with the plaintiff's contract rights of suc
as to warrant legal sanction? If it is considered tha
be imposed on the strength of the two factors, attenti
distinct tort of unlawful interference with trade or bus
of unlawful means.

3. Venturing beyond contractual rights

The paradigm situation in which the tort is invoked is where a defendant

intentionally causes a third party to breach a contract with the plaintiff so
as to interfere with the plaintiffs contractual rights.56 However, the tort
applies to many other rights which are conferred by law. This is only logical
as there is nothing peculiar about a contractual right which justifies
according to it more protection than other rights; the tort is wide enough
to include civil rights existing independently of contract.57 For example,
the operation of the tort extends to rights58 such as the plaintiffs right to

Carty, supra, note 1, at 257. Some support for this may be derived from Millar v Bassey,
supra, note 47.
See Speight J, in a slightly different context, in Pete's Towing Services Ltd v Northern
Industrial Union, supra, note 49, at 46-47.
See Sales, The Tort of Conspiracy and Civil Secondary Liability [ 1990] CLJ 491 who
advances the view that the tort is based on civil secondary liability. This was accepted by
Lord Hoffmann, The Redundancy Of Knowing Assistance in Birks (ed), The Frontiers Of
Liability (1994), vol 1 at 12.
Dixon J, James v Commonwealth ( 1939) 62 CLR 339 at 370; Sir Bingham MR, Law Debenture
Trust Corp v Ural Caspian Oil Corp Ltd [1994] 3 WLR 1221 at 1230-1231, citing with
approval a passage from Fleming, supra, note 2, at 689-690.
Parental rights are not included: F v Wirral Metropolitan Council [1991] 2 WLR 1132.
The tort may also be the basis for protecting the right to vote (Ashby v White (1702) 2 Ld
Raym 9380 and the common law right to reasonable accomodation at an inn (Constantine
v Imperial Hotels Ltd [1944] KB 693).

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SJLS A Perspective on the Economic Torts 495

the benefit of the performance of a statutory59 or com

a third party and to copyright protection.61 The defenda
if he knowingly interferes with the plaintiffs right to
injunction.62
Further, the tort may not be concerned solely with the pr
whether contractual or otherwise. It has been established th
will be liable as long as he knowingly interferes with t
contract, even if no breach of contract results.63 For ex
has been held liable if he interferes with the plaintiff's
formance by unlawful means and causes the plaintiff to
in order to honour his contractual obligations.64 Similarl
unlawfully causes the plaintiffs contract with a third par
is liable to the plaintiff, even though the third party i
plaintiff by reason of a force majeure clause.65 It has b
however, that the cases in which this rule has been appli
involve interference with contractual rights by unlawf

Meade v Haringey London Borough Council [1979] 1 WLR 637; A

v Wade [1979] 1 WLR 697; Barrets and Baird (Wholesale) Ltd v In
Civil Servants, supra, note 46; Associated British Ports v Transpor
Union [1989] 1 WLR 939, reversed, ibid, 970 without affecting t
James v Commonwealth, supra, note 33 (common carrier's duty)
CBS Songs Ltd v Amstrad Consumer Electronics pic, supra, note
Acrow (Automation) Ltd v Rex Chainbelt Inc [ 1971 ] 3 All ER 1175 ; Beld
Trust Corp v Ural Caspian Oil Corp Ltd, supra, note 57, at 1235. In
defendants were restrained from abetting a breach of an injunction obta
against a third party. The court granted the injunction on the ground
just cause or excuse, deliberately interfered with the trade or busine
unlawful means. However, it is difficult to justify this as, on the ev
did not intend to cause harm to the plaintiffs; Balkin & Davis, Law o
The more supportable analysis is that the defendants were liable for
with the plaintiffs' right to be protected by the injunction. By anal
down in the normal cases involving contracts, it would be sufficient
of the existence of the injunction and that their actions would inter
conferred thereunder. C/the earlier cases of Chapman v Honig [ 1963] 2 Q
v Bretherton [1959] 1 QB 45.
Torquay Hotel Co Ltd v Cousins, supra, note 48, at 138; Einhorn v We
Ltd ( 1969) 6 DLR (3d) 71 ; Wolley v Dunford, supra, note 48, at 2
Ltd v Kingswood Motors (Addlestone) Ltd [1974] 1 QB 142 at 155; D
note 48, at 98; Greig v Insole, supra, note 44, at 332; MacKenzi
1 NZLR 670; Merkur Island Shipping Corporation v Laughton, su
Loh Holdings Sdn Bhd v Peglin Development Sdn Bhd [1984] 2 M
NSW Pty Ltd v Frost, supra, note 48, at 68,611 ; Law Debenture Trus
Oil Corp Ltd, supra, note 57, at 1232-1233; Mok Tai Dwan v Ke
Kereta Sdn Bhd, supra, note 39, at 615-616.
Dimbleby & Sons v National Union of Journalists [1984] 1 WLR
Torquay Hotel Co Ltd v Cousins, supra, note 48.

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496 Singapore Journal of Legal Studies [1996]

in fact be no more than instances of the tort of unlawful interference with

trade or business.66 To a large extent, this proposition cannot be disputed.

In the case of interference with contract short of causing a breach, there
is no violation of a legal right; only contractual expectations are involved.
It would surely be extending the tort too far if intentional interference (as
opposed to malicious or spiteful interference) with economic expectations
were to be actionable. Thus, generally no liability ensues if, without resorting
to unlawful means, the defendant procures a third party not to contract with
the plaintiff.67 Neither is it an actionable interference for a defendant to
take a transfer of property from a third party and so prevent the plaintiff
from applying for injunctive relief against the third party to restrain him
from transferring that property.68 Also, no liability is imposed on a defendant
whose intentional conduct devalues the economic advantages attached to
the plaintiffs right (without any actual interference with the right itself).69
On the other hand, it is submitted that there should be liability for
malicious interference with contractual performance or other expectations.
In MacKenzie v MacLachlan,70 there was a personal dispute between the
defendant, the general manager of a city council, and the plaintiff, who
was an engineer employed by the council. The plaintiff alleged that the
defendant's conduct towards him was oppressive and arbitrary, that the
defendant had unjustifiably harassed him and that he had suffered injury
to his reputation. The defendant's application to strike out the plaintiff's
claim for damages and injunctive relief was refused on the ground that
it was clearly arguable that the defendant could be liable for such in
terference with the plaintiff's contract of employment. In Thomas v National
Union of Mineworkers (South Wales Area),71 a mineworkers' union was
held liable when its pickets verbally abused and threatened violence against
the plaintiff workers who had decided to go back to work. Scott J based

See Clerk & Lindseil on Torts, supra, note 2, at para 23-19 and the writings cited at note
71 therein.

The main authorities usually cited being Allen v Flood, supra, note 7; McKernan v Fraser,
supra, note 32; Midland Cold Storage v Steer [1972] Ch 630 at 643-645. Cf Gershman
v Manitoba Vegetable Producers' Marketing Board (1976) 69 DLR (3d) 114.
Law Debenture Trust Corp v Ural Caspian Oil Corp Ltd, supra, note 57. See Cane, Tortious
Interference With Contractual Remedies (1995) 111 LQR 400.
See RCA v Pollard, supra, note 41 (bootlegger not liable for making plaintiffs copyright
less valuable); Victoria Park Racing And Recreation Grounds Co Ltd v Taylor (1937) 38
CLR 479 (defendant not liable for simultaneous broadcast of the descriptions of races
conducted by plaintiff on neighbouring land which caused a reduction of attendances at
the plaintiffs races).
Supra, note 63.
[1985] 2 WLR 1081 at 1107-1109. CfNews Group Newspapers Ltd v SOGAT '82 [1987]
ICR 181 at 205-6 and Patel v Patel [1988] 2 FLR 179.

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 SJLS A Perspective on the Economic Torts 497

his decision on the ground that there was an unreasona

the plaintiffs' right to go to work.72 Finally, in Gershman
Producers' Marketing Board,73 the plaintiff entered in
of a company in anticipation of an agreement to pu
that company from its shareholders. The defendant Bo
against the plaintiff, cancelled the company's credit a
restore it as long as the plaintiff continued to be emplo
As may be expected, this caused the plaintiff's plans t
of the company to be abortive. The court found th
although, on the facts, there had clearly been interfe
anticipated contract. The court's reasoning, howeve
liability for interference with an anticipated contract. I
that the plaintiff did not lose the opportunity for m
the opportunity to extend his already existing contrac
employment into one that would include acquisition
analysis was obviously not in accord with the reality o
more importantly, with the fact that the contract of e
the company while the anticipated contract of acquisit
with the shareholders of the company. It would be fa
unorthodox approach was taken solely to evade the per
is not a tort for a defendant to injure his economic ex
the defendant acted maliciously.
It is difficult to dispute that the above decisions were
it would be most unjust if the respective plaintiffs' g
remedy at law. Y et, if one were to accept that there is no lia
with economic expectations unless unlawful means
have to come to the unsettling conclusion that person
maliciously victimised are indeed remediless. It is there
there has been some recognition, although not as e
like, that malicious damage to economic expectatio

4. Justification

The defence of justification to interference with contra

The authorities have shown that it is insufficient that there is absence of
malice or ill-will or intention to injure the person whose contract is broken,
that the defendant acted in the commercial or other best interests of himself

72
Scott J suggested that such interference might be a species of private nuisance but he felt
that the label for the tort did not matter.
73 Supra, note 67. However, the decision recently met with a cool response in the Ontario
Divisional Court in Daishowa Inc v Friends of the Lubicon, supra, note 17.

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498 Singapore Journal of Legal Studies [1996]

or the contract breaker, or that the plaintiff has br

the defendant and the defendant is effecting 'reven
procuring a breach of the plaintiff's contract with a
other hand, justification may be established if the d
pursuant to a moral duty, if the defendant is procuring
between the plaintiff and a third party which is inco
contract between the defendant and the plaintiff,75 if
in protection of his equal or superior legal right,76 or, p
is acting in the public interest.77 On the whole, the
has rarely been successfully invoked to excuse an inte
The reason is that the contracting party's interest in
public interest in security of contracts tend to be rega
than an interest in liberty to trade.78
These instances do not reveal any general princ
justification defence other than that it must be r
account all relevant factors, for the defendant to ha
rights of the plaintiff. What amounts to justificatio
the 'good sense of the tribunal';80 regard must be ha
contract broken, the position of the parties to the b
the person procuring the breach to the person who br
the object of the person in procuring the breach.81 It
that the defence has been said to be notoriously unst

See the summary in Edwin Hill & Partners v First National Finan
note 43, at 230-1 and the cases cited therein. See also Pritchard
at 415-417.

See the summary in Edwin Hill & Partners v First National Finance Corporation pic, supra,
note 43, at 230-1. See also Dellabarca v Storemen & Packers Union [1989] 2 NZLR 734
at 753-754.

Edwin Hill & Partners v First National Finance Corporation pic, supra, note 43, approving
the dictum of Darling J in Read v Friendly Society of Operative Stonemasons of England,
Ireland and Wales [1902] 2 KB 88 at 96-7.
See, eg, Brimelow v Casson [1924] 1 Ch 302; Posluns v Toronto Stock Exchange (1964)
46 DLR (2d) 210, (1966) 53 DLR (2d) 193.
Heydon, The Defence Of Justification In Cases Of Intentionally Caused Economic Loss
(1970) 20 UTLJ 139 at 171.
For a comprehensive discussion see Heydon, supra, note 78, at 171.
Bowen LJ in Mogul SS Co v McGregor, Gow & Co, supra, note 11, at 618; Romer LJ
in Glamorgan Coal Co Ltd v South Wales Miners' Federation [1903] 2 KB 545 at 574,
affirmed, supra, note 39; Greig v Insole, supra, note 44, at 340-341; Stuart-Smith LJ in
Edwin Hill & Partners v First National Finance Corporation pic, supra, note 43, at 229.
Romer LJ in Glamorgan Coal Co Ltd v South Wales Miners' Federation, supra, note 80,
at 574, affirmed supra, note 39; Stuart-Smith LJ in Edwin Hill cê Partners v First National
Finance Corporation pic, supra, note 43, at 229.
Gardner, The Proprietary Effect Of Contractual Obligations Under Tulk v Moxhay And De
Mattos v Gibson (1982) 98 LQR 279 at 290.

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SJLS A Perspective on the Economic Torts 499

taking into account the countless ways in which interf

or other rights may take place, it is futile to hope for
principles. Indeed, it is the very elasticity of the d
encourage the development, modification and refinem
of liability to meet novel or difficult situations.

5. Knowing implication in breach of trust or fiduciary

In equity, certain principles of liability bear a strong

tort of interference with contractual and other right
whether these principles should be amalgamated with
tortious principles merits attention. The equitable wron
implicated in a breach of trust or fiduciary duty is one
who has dishonestly assisted in a breach of trust or fid
to account to the beneficiary for his loss, irrespective of
person also acted dishonestly or fraudulently.83 The p
same if he takes the initiative and knowingly induces
or fiduciary duty.84 Similarly, a defendant is liable for
of an equitable obligation to account owed to the plain
Putting aside the distinctive terminology of the equit
is evident that the principle of liability in all these
fundamentally the same as in the tort of interference
The similarity between the content of the two princ
context in which their application would usually arise
in Watson v Dolmark Industries Ltd.ib The defendant in
substantial proprietor of a company which had been gr
and marketing rights by the plaintiff for a certain ty
tray, in consideration for royalties calculated by refer
of trays manufactured. The defendant, acting on beha
dishonestly under-declared to the plaintiff the numbe
by the company in order to avoid paying the full roy
plaintiff would have been entitled. The company then u
to manufacture and sell a similar product. On facts
probable that an action for interference with rights w
against the defendant for the amount of royalties wh

Royal Brunei Airlines v Tan [1995] 2 AC 378. See also Birks, Acc
LMCLQ 1 and Harpum, The Basis Of Equitable Liability in Birks
Liability (1994), vol 1.
See the discussion and authorities cited by Harpum, supra, note
Prudential Assurance Co Ltd v Lorenz (1971) 11 KIR 78.
[1992] 3 NZLR 311.

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500 Singapore Journal of Legal Studies [ 1996]

the plaintiff.87 As it turned out, however, the defend

and decided on the basis of knowing implication in
duty.
Keeping the two principles artificially apart by labelling them tortious
and equitable cannot be good for the development of the law. The concept
of interference in the tort is, by now, probably wide enough to encompass
all forms knowing implication in a breach of trust or fiduciary duty. Further,
a person's rights under a trust or pursuant to a fiduciary duty owed to him
are clearly capable of being protected under the tortious principles. As Lord
Hoffman, writing extra-judicially, points out, fiduciary obligations and
contractual obligations are merely species of obligations and it should be
possible to assimilate or at least to reconcile the two forms of liability.88
The proposition that there is no tort known as inducing a breach of trust89
or, presumably, also a breach of fiduciary duty, may have to be re-considered
in the not-too-distant future.

6. The rule in De Mattos v Gibson

Another equitable principle which has strong parallels with the tort of
interference with rights is, of course, the infamous rule in De Mattos v
Gibson.90 In this case, a mortgagee of a ship who, prior to taking the
mortgage over the ship, had knowledge of a charterparty entered into
between the shipowner and a hirer, was restrained from enforcing his
security over the ship on the ground that this would interfere with the
performance of the charterparty. The principle espoused was that a person,
who acquires movable or immovable property from another with knowl

There is a rule that an agent who interferes with the contractual relations between his principal
and a third party is not liable as he is the alter ego of his principal and his acts are in law
the acts of his principal. But this rule does not apply in the instant case as the defendant
was not acting bona fide within the scope of his authority: see Said v Butt [1920] 3 KB
497 at 506; G Scammell & Nephew Ltd v Hurley [ 1929] 1 KB 419 at 443 and 449; O 'Brien
v Dawson (1942) 66 CLR 18 at 32 and 34; DC Thomson & Co Ltd v Deakin, supra, note
49, at 680-681; Rutherford v Poole [1953] VLR 130 at 135-6; Official Assignee v Dowling
[1964] NZLR 578 at 580-581; Telemetrix pic v Modern Engineers of Bristol (Holdings)
pic [1985] BCLC 213 at 217; Welsh Development Agency v Export Finance Co Ltd [1992]
BCLC 148.
Hoffmann, supra, note 56, at 12.
Metall und Rohstoff AF v Donaldson Lufkin & Jenrette Inc [1990] 1 QB 391. In Crawley
Borough Council v Ure [1995] 3 WLR 95 at 106, Glidewell LJ specifically declined to
decide on the corectness of this proposition. See also Hoffmann J (as he then was), Law
Debenture Trust Corp v Ural Caspian Oil Corp Ltd, supra, note 40, at 151.
(1858) 4 De G&J 276.

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SJLS A Perspective on the Economic Torts 501

edge91 of a previous contract92 made by the latter with

and employ the property for a particular purpose, cann
the property in a manner which is inconsistent with th
detriment of the third party. He may be restrained from do
relief,93 but he will not be ordered to positively perform
contract.94
The principle received Privy Council sanction on one occasion95 but was
subject to considerable criticism by other courts.96 In particular, its
application was rejected in relation to resale price maintenance agreements,
and a sub-purchaser was held not to be liable if he sold the purchased goods
below a certain price with the knowledge that this would place the purchaser
in breach of a price maintenance agreement with the supplier.97 However,
more recent cases have established that the principle remains good law
today.98
The similarity between the De Mattos principle and the tort of interference
with contract is striking, to say the least. Where a writer contracted to transfer
future copyright exclusively to the plaintiff publisher, a rival publisher was
restrained on the De Mattos principle from publishing the relevant works.99
On the other hand, where purchasers, who bought cars from the plaintiff
on condition that they were not to be re-sold within a year, proceeded to
sell them to the defendant in breach of this condition, the defendant was
held liable for inducing the purchasers to breach their contracts with the

Only actual notice will do: Swiss Bank v Lloyds Bank [1979] Ch 548 at 575: Mac-Jordan
Construction Ltd v Brookmount Erostin Ltd [1992] BCLC 350.
This need not a specifically enforceable contract: Lord Shaw, Lord Strathcona Steamship
Co v Dominion Coal Co [1926] AC 108 at 125.
Lord Shaw, Lord Strathcona Steamship Co v Dominion Coal Co, supra, at 119.
Law Debenture Trust Corp v Ural Caspian Oil Corp Ltd, supra, note 40.
Lord Strathcona Steamship Co v Dominion Coal Co [1926] AC 108. The Privy Council
applied the principle to grant a similar injunction against a purchaser of a ship.
Barker v Stickney [1919] 1 KB 121; Greenhalgh v Mallard [1943] 2 All ER 234 at 239:
Port Line Ltd v Ben Line Steamers Ltd [ 1958] 2 QB 146. The Australian courts have expressed
similar sentiments: Sweeney v Tristam [1936] St RQd 129 at 134: Rutherford v Poole [1953]
VLR 130 at 141-142; Howie v New South Wales Lawn Tennis Club (1955) 95 CLR 132
at 156.

Taddy v Sterious [1904] 1 Ch 354; McGrunther v Pitcher [1904] 2 Ch 306. See also Chan
Sek Keong J in Beecham Group pic v Chinheh Trading (S) Pte Ltd Suit No 2454 of 1991
(10 April 1992, Singapore High Court, unreported), cited by Tjio, Clogs On Commerce
(1994) 6 SAcLJ at 167.
The existence of the principle was approved in Swiss Bank v Lloyds Bank, supra, note 91,
at 575; The Myrto [1977] 2 Lloyds Rep 243; Mac-Jordan Construction Ltd v Brookmount
Erostin Ltd, supra, note 91 ; Law Debenture Trust Corp v Ural Caspian Oil Corp Ltd, supra,
note 57.

Erskine MacDonald Ltd v Eyles [1921] 1 Ch 631.

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502 Singapore Journal of Legal Studies [1996]

plaintiff.100 Furthermore, where the plaintiff financ

on the security of the shares and on condition that
be used as security in favour of any other person, a
security over the shares with actual notice of such co
under both the De Mattos principle and the tort of interf
Not surprisingly, the courts have occasionally tend
two principles. The De Mattos principle has been desc
counterpart of the tort of knowing interference with
and, more recently, it was held that the grant of
restrained on the application of the principle be
interference with the chargor's contractual rights.103
sooner the assimilation is completed the better, on
trovertible basis that principles of liability which co
stantially the same ground should not be kept distinc
formalistic considerations.
Such a submission is likely to meet with a hostile reception from the
prevailing academic view104 that the De Mattos principle should not be
conflated with the tort.105 One objection raised is that liability under the
former is more extensive than the latter; it is said that it is not a tort for
a defendant, acting lawfully, to cause a third party to break his contract

100 British Motor Trade Association v Salvadori, supra, note 40, approved in Rickless v United
Artists Corporation, supra, note 40.
101 Swiss Bank v Lloyds Bank, supra, note 91, reversed on the facts at [1982] AC 584.
102 Browne-Wilkinson J (as he then was), Swiss Bank v Lloyds Bank, supra, note 91, at 575.
See also the Canadian decision of Banco do Brasil SA v Pan American Steamship Lines
lnc [1992] 3 FC 735 where it was apparently assumed by the court that the De Mattos
principle, as interpreted in The Myrto [1977] 2 Lloyd's Rep 243, was based on the tort
of inducing breach of contract.
103 Mac-Jordan Construction Ltd v Brookmount Erostin Ltd, supra, note 91, at 357. This
conclusion was sound, since the relevant contractual rights did not relate to any specific
property comprised in the charge, and this is also the basis of distinction between this decision
and De Mattos. C/the views expressed by Clarke, De Mattos v Gibson Again [ 1992] LMCLQ
448.

104 Tettenborn, Covenants, Privity Of Contract AndThe Purchaser OfPersonal Property] 1982]
CLJ 58; Gardner, supra, note 82; Clarke, supra, note 103; Swaddling, Ch 1, Interests In
Goods (1993, eds Palmer and McKendrick) at 6. A fair number of commentators, however,
have taken the opposite view that the De Mattos principle is based on the tort of interference
with contract: see Wade (1926) 42 LQR 141; Treitel, Limited Interests In Chattels (1958)
21 MLR 422; Cohen-Grabelsky, Interference With Contractual Relations And Equitable
Doctrines (1982) 45 MLR 241.
105 It has been suggested that the De Mattos principle rests on the doctrine of unjust enrichment:
Tettenborn, supra, note 104. Another view is that the principle is an application of the land
law doctrine of restrictive covenants to ships: Salleh Abas FJ, Tarn Kam Cheong v Stephen
Leong Kon Sang [ 1980] 1 MLJ 36 at 40. This is very doubtful, as the notions of a proprietary
interest and a dominant tenement are nonsensical in the context of personalty.

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 SJLS A Perspective on the Economic Torts 503

with the plaintiff, as was the case in De Mattos.106 Thi

on the view that such an act would be indirect interference with contract

which requires unlawful means for it to be actionable. However, it is by

no means clear that this is an indirect interference. For example, where
the defendants acquired control of a company and prevented it from
performing a contract obligation owed to the plaintiff, they were held to
have directly interfered with the contract.107 Furthermore, as suggested earlier,
the better view is that even if it is strictly an indirect interference it does
not follow that unlawful means are always required; the intention of the
defendant and the causative proximity of the interference would have to
be considered. A second objection is that the De Mattos principle pre-dates
that established in Lumley v Gye,m but surely this is not a good ground
for not consolidating them into one single coherent doctrine if it is otherwise
desirable to do so. Such a consideration certainly did not dissuade the High
Court of Australia from deciding that the nineteenth century rule in Rylands
v Fletcher109 was to be absorbed by modern negligence principles.110 A third
objection is that De Mattos does not apply to contracts involving land, but
the tort of interference with contract does."1 However, this only shows that
De Mattos may in some situations be narrower in application than the tort
and does not really conflict with the suggestion that De Mattos should be
subsumed under tortious principles.
Further, if the view that De Mattos should be subsumed under the tort
is accepted, the rejection of De Mattos in relation to the price maintenance
cases may be plausibly explained on the ground that the defence of justification
was applicable in those cases. While price maintenance agreements are
enforceable inter partes,112 they are probably contrary to public interest and
the security of trade to enforce price maintenance agreements against third
parties who are strangers to the price maintenance agreement.113 A sub
purchaser who, strictly speaking, procures a breach of the price maintenance
agreement by the purchaser can probably claim justification on this ground.

106 Tettenborn, supra, note 104, at 82-83; Swaddling, supra, note 104, at 16.
107
Esso Petroleum Co Ltd v Kingswood Motors (Addlestone) Ltd, supra, note 63.
108 Gardner, supra, note 82, at 292-293.
109 (1866) LR 1 Ex 265, affirmed (1886) LR 3 HL 330.
110 Bumie Port Authority v General Jones Pty Ltd (1994) 120 ALR 42.
111 Gardner, supra, note 82, at 292.
112 Elliman v Carrington [1901] 2 Ch 275.
113 As pointed out by Tettenborn, supra, note 104, at 67, citing Lord Shaw, National Phonograph
Co v Menck [1911] AC 336 at 347.

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 504 Singapore Journal of Legal Studies [1996]

IV. Intimidation

1. General principles

The tort of intimidation is committed when a defendant threatens to

commit an unlawful act against another person, so as to compel the latter

to do something which he would not otherwise do or to refrain from doing
something which he would have refrained from doing, and which thereby
causes damage to the plaintiff."4 It must be shown that the defendant's
object was to injure the plaintiff"5 and the defendant must have intended
to compel the plaintiff to take a particular course of action."6 Unlawful
acts for the purpose of intimidation would clearly include illegal and tortious
acts. Thus, a defendant who fired his cannons at African natives who were
attempting to trade with the plaintiff and frightened them away was liable
to the plaintiff for his loss of trade."7
Further, it is established that even a breach of contract is an unlawful
act."8 Where the defendants threatened their employer that they would go
on strike in breach of their contracts of employment unless the employer
terminated the employment of the plaintiff, and the employer succumbed
to the demand and discharged the plaintiff, the defendants were liable for
intimidation to the plaintiff."9 It should be noted that the extension of
intimidation to a threat of breach of contract does not undermine the doctrine
of privity; privity of contract only prevents the plaintiff from suing on a
contract to which he is not a party, and does not prohibit him from suing
in respect of a tort committed against him by the defendant.120

2. Justification

Since the tort of intimidation by definition requires an unlawful threat,

a threshold question as to the applicability of the justification defence is
whether unlawful acts can ever be justified. There is a view that they can

1,4 James v Commonwealth, supra, note 33; Rookes v Barnard, supra, note 6; Morgan v Fry
[1968] 2 QB 710 at 724; Central Canada Potash Co Ltd v Government Of Sasketchewan
(1978) 88 DLR (3d) 609; Latham v Singleton [1981] 2 NSWLR 843; Hadmor Productions
Ltd v Hamilton [1983] AC 191.
115 Lord Devlin, Rookes v Barnard, supra, note 6, at 1208; Martland J, Central Canada Potash
Co Ltd v Government Of Sasketchew an, supra, note 114, at 642.
116 Huljich v Hall [1973] NZLR 279 at 285.
117 Tarleton v M'Gawley (1794) Peake 270.
118
Rookes v Barnard, supra, note 6.
119 Rookes v Barnard, supra, note 6.
120 See Lord Reid, Rookes v Barnard, supra, note 6, at 1168. See also Hoffmann, Rookes v
Barnard (1965) 81 LQR 116 at 124-128 and Rogers, supra, note 2, at 510-512.

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SJLS A Perspective on the Economic Torts 505

never be justified,121 but probably the preferable positi

be justified in appropriate circumstances. As Heydon poin
be said that all unlawful acts in all circumstances are mo
malicious or harmful, and there is in fact no sustainabl
that they can never be justified. The truth is that ther
unlawful acts of which the nature, culpability and cons
differing; this is all the more so with the modern pervasi
and regulation. Furthermore, it is perhaps easily con
might be situations, analogous to self-defence, which m
of unlawful means to protect one's interests. The possibi
should not depend on whether there is some independen
facts, but on the seriousness and social inutility of what ha
While acknowledging that it is somewhat distasteful to h
act may be justified, the reality is that the justification
because of the wide meaning of unlawful threats that h
Allowing the justification defence is, on balance, more
arbitrarily restricting the category of unlawful threats.
The weight of authority also suggests that justificatio
a defence to intimidation. It has been said that intimidat
in a situation such as where defendant unionists are
'troublemakers who fomented discord in the docks without lawful cause
of excuse'.124 Justification has been accepted as a defence to intimidation
in Australia.125 One may expect that, as in the case of justification in the
other economic torts, it would be impossible to draw any definite or precise
guidelines as to the operation of the defence. Indeed, it has been likened
to the justification defence in the context of interference with contract: it
is to be determined by the good sense of the court in the individual
circumstances of each case.126 Relevant factors which the court would look
at would presumably include the nature of the threat, the relationship between
the parties, the purpose sought to be achieved by the defendant and the
respective positions of the plaintiff and the defendant. It is to be made clear,
however, that justification to intimidation will in the great majority of cases
be much harder to establish than justification to interference with contract,

121 See the dicta referred to by Heydon, supra, note 78, at note 271.
122 Heydon, supra, note 78, at 177-182.
123 Heydon, supra, note 78, at 182.
124 Lord Denning, Morgan v Fry, supra, note 114, at 729. Lord Devlin left open the possibility
of justification applying to intimidation in Rookes v Barnard, supra, note 6, at 1206 and
1209. See also Lord Denning, Cory Lighterage v TGWU [1973] ICR 339 at 356-357.
125 Latham v Singleton, supra, note 114. For the more tentative New Zealand position, see
Dellabarca v Northern Storemen and Packers Union, supra, note 75, at 750-751.
126 Latham v Singleton, supra, note 114, at 867-870.

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506 Singapore Journal of Legal Studies [1996]

given that what is sought to be justified is an act wh

not at liberty to commit.

3. Three-party and two-party intimidation

The normal case of intimidation is where A makes an unlawful threat

to B thereby causing him to act to the prejudice of C. It is unsettled whether
intimidation may be constituted in a two-party situation. There is dicta that
it may.127 Certainly, there does not seem to be any reason why two-party
intimidation should not be allowed in a case such as where, for example,
a plaintiff trader is compelled to discontinue his business by means of
intentional threats of personal violence made against him by the defendant.128
Indeed, it seems reasonably clear that where what is threatened is a tort,
as opposed to a mere breach of contract, liability may arise in a two-party
situation.129
Controversy arises, however, where the threat is one of a breach of
contract. As has been seen, a threat to break a contract in a three-party
situation is clearly sufficient to amount to intimidation. In a two-party
situation, such a threat raises problems relating to the boundaries between
contract and tort law. It has been said that, if two-party intimidation can
arise with respect to a threatened breach of contract, it must follow that
an intentional breach of contract will always amount to the tort of unlawful
interference with trade. This would conflate tortious and contractual li
ability.130 While this proposition is undeniably true and dictates the con
clusion that it is superfluous to render it a tort to breach a contract in
tentionally, it does not follow that it is unnecessary for there to be a tort

127 Lord Devlin, Rookes v Barnard, supra, note 6, at 1205; Lord Denning MR, D&C Builders
v Rees [1966] 2 QB 617 at 625 and JT Stratford & Son Ltd v Lindley, supra, note 39, at
283. Note, however, the reservations of Lord Reid, JT Stratford & Son Ltd v Lindley, supra,
note 39, at 325. For similar dicta in the Australian and New Zealand courts , see: Williams
v Hursey (1959) 103 CLR 30 at 77; Pete's Towing Services Ltd v Northern Industrial Union,
supra, note 49, at 41-2; Huljich v Hall, supra, note 116, at 285; Latham v Singleton, supra,
note 114, at 858.
128 Dixon J, James v Commonwealth, supra, note 33, at 374; Lord Devlin, Rookes v Barnard,
supra, note 6, at 1205-1206. See also The Tubantia [1924] P 78. C/Hoffman, supra, note
120, at 127-128 where he suggests that where such threats are made against the plaintiff
he should resort to other remedies such as a quia timet action or an action in restitution.
With respect, it is submitted that the former may not always be practical and a restitutionary
action is not appropriate where the plaintiff is made to suffer a detriment without a
corresponding benefit being obtained by the defendant.
129 Mintuck v Valley River Band (1977) 75 DLR (3d) 589; Martland J, Central Canada Potash
Co Ltd v Government Of Sasketchewan, supra, note 114, at 640.
l30Carty, supra, note 1, at 261-262.

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SJLS A Perspective on the Economic Torts 507

of threatening a breach of contract. In the case of a threa

there is no confusion at all between tortious and cont
contractual liability arises simply because the contract
any injury which the plaintiff suffers is not by reaso
contract but is due to the threat of the defendant.
A second argument is that the law should not encourage the plaintiff
to yield to the defendant's threat of breach of contract but should persuade
him to resist it; if the defendant carries out his threat the plaintiff always
has his contractual remedies.131 While this contention has some merit, it
is respectfully suggested that it is based on a policy which the law has
abandoned, having fairly recently taken up the position that economic
duress may vitiate a contract or give rise to a restitutionary remedy. On
another note, however, the advent of the doctrine of economic duress
appears to be a formidable argument against liability for intimidation in
a iwo-party situation arising out of a threat of breach of contract. This
argument certainly deserves attention.

4. Two-party intimidation and economic duress

The view has been advanced that, in the case of a threatened breach
of contract involving two parties, tort protection is not necessary as there
is already the restitutionary action for economic duress.132 After all, most
of the economic duress cases have arisen out of situations where a defendant,
who is a party to a contract, issues a threat to the other party, the plaintiff,
that he (the defendant) would breach the contract unless the plaintiff agrees
to vary the contract to the his benefit, and the plaintiff yields to this threat
and agrees to the demanded variation.133
However, to simply say that the doctrine of economic duress renders
liability for intimidation unnecessary is unsatisfactory. Applying estab
lished principles, tortious liability for intimidation arising out of a threatened
breach of contract, if available vis-à-vis two contractual parties, is easier
to establish than economic duress. Intimidation would always be established
whenever a threat to breach a contract is made by one contractual party
to the other which causes the threatened party to submit to the other's

131 Martland J, Central Canada Potash Co Ltd v Government Of Saskatchewan, supra, note
114, at 640, citing with approval a passage from Winfield and Jolowicz on Tort (10th Ed),
at 458.

132 Carty, supra, note 1, at 261-262.

133 See, eg, North Ocean Shipping Co Ltd v Hyundai Construction Co Ltd [1979] QB 705;
Pao On v Lau Yiu Long [1980] AC 614; B&S Contracts and Design Ltd v Victor Green
Publications Ltd [1984] ICR 419; Atlas Express Ltd v Kafco Ltd [1989] QB 833; The Alev
[1989] 1 Lloyd's Rep 138.

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508 Singapore Journal of Legal Studies [ 1996]

demands. But economic duress is not always presen

There is an additional inquiry into the impact of the
will of the threatened party: the courts have been co
whether there was also a coercion of the will of the t
as to vitiate his consent134 or whether he was left w
reasonable alternative.135 Factors such as whether
protested, whether he had access to independent ad
took steps to avoid the consequences of his subm
considered.136
The real question, therefore, is why the doctrine of
deemed to be more appropriate than the tort of intim
The answer is probably one based more on form t
Despite the criteria for economic duress laid down b
clear that ultimately a decision in an economic duress c
balance of two competing interests. On the one hand,
in preserving the sanctity of a contract freely entere
on the other, there is the interest in allowing bona f
the terms of a contract where changed circumstances m
terms to be extremely harsh on one party. It is an is
which involves consideration of all the circumstances
been expressly identified and others of which the
articulate. Factors in the latter category may include t
have traditionally been reluctant to include as a judici
example, the reasonableness of the re-negotiated term
ableness of the original terms. This may explain th
the cases on economic duress are not consistent with each other or with
the express criteria that have been laid down.137
It is submitted that, in an approach based on two-party intimidation, the
same underlying policy concerns would have to be addressed but from a
different angle: they would be considerations which have to be taken into

134 Kerr J, The Siboen and the Sibotre [1976] 1 Lloyd's Rep 293 at 336; Lord Scarman, Pao
On v Lau Yiu Long, supra, note 133, at 635-636; Moyes & Groves Ltd v Radiation New
Zealand Ltd [1982] 1 NZLR 368; Lord Scarman, The Universe Sentinel [1983] 1 AC 366
at 400. This test has been criticised; see Atiyah, Duress and the Overborne Will (1982)
98 LQR 197; McHugh JA, Crescendo Management Pty Ltd v Westpac Banking Banking
Corp (1988) 19 NSWLR 40 at 45-46; Birks, Introduction To The Law Of Restitution (1989)
at 183. It is probably no longer in favour.
'35 Lord Scarman, The Universe Sentinel, supra, note 134, at 400; Griffiths LJ and Kerr J, B&S
Contracts and Design Ltd v Victor Green Publications Ltd, supra, note 133, at 426 and
428 respectively; The Alev, supra, note 133, at 146-147.
136 Lord Scarman, Pao On v Lau Yiu Long, supra, note 133, at 635-636.
137 See, eg. Burrows, The Law Of Restitution (1993) at 174-182; Phang, Whither Economic
Duress? (1990) 53 MLR 107.

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SJLS A Perspective on the Economic Torts 509

account in determining whether the defence of justific

defendant's threat of breach of contract does not amount
it must correspondingly be the case that his unlawful th
the circumstances of the case. If his threat does amount
it must mean that he was not justified in making it. In o
for economic duress and two-party intimidation are to
the formal route by which liability is established in
different. Thus, Lord Scarman thought that economic dur
the relevant transaction void but is also actionable as a tort if it causes
damages or loss.138
Of course, this is not to say that the economic duress doctrine should
be jettisoned in favour of an analysis based on the tort of intimidation.
The economic duress analysis should continue to be utilised. The guidelines
on economic duress that have been laid down by the courts in such cases,
though lacking in clarity and comprehensiveness, are nevertheless of some
assistance to the task at hand. In contrast, the intimidation analysis centres
on the very indistinct concept of justification. In a developing area of the
law in which there are relatively few case authorities, a more structured
approach is better than a less structured one. In any event, the analysis
based on economic duress has been well-entrenched in the authorities, and
any attempt to argue that it should be discarded would be academic.
What the suggested approach seeks to achieve, then, is twofold. Firstly,
it attempts to remove any theoretical difficulty as to why, contrary to
established principles, no liability for intimidation apparently arises in cases
of threatened breaches of contract in a two-party situation. Secondly, it
asserts that there is no difference in the content of the principles to be applied
whether the plaintiff is seeking to vitiate a contract or to the restitution
of a benefit, or he is claiming damages for losses incurred. The orthodoxy
is that economic duress applies only in the former situation. However, it
should not make any difference that the plaintiff is claiming damages rather
than rescission or restitution; surely the moral claim of a wrongfully injured
plaintiff is at least as strong as that against an unjustly enriched defendant.
Yet, if economic duress does not perse amount to a tort,139 the uncomfortable
conclusion is that the injured plaintiff is indeed worse off. The suggested
approach would eliminate this difficulty.

138 The Universe Sentinel, supra, note 134, at 400. Admittedly, this is not the favoured view,
which is that economic duress is not a tort per se: Lord Diplock, ibid, at 385; Lord Goff,
The Evia Luck (No 2) [1992] AC 152 at 166. See also Carty and Evans (1983) JBL 218
at 224; Birks, The Travails Of Duress [1990] LMCLQ 342.
139
Lord Diplock, The Universe Sentinel, supra, note 134, at 385; Lord Goff, The Evia Luck
(No 2), supra, note 138, at 166.

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 510 Singapore Journal of Legal Studies [1996]

V. Conspiracy

1. General principles

There are two types of conspiracy: conspiracy by unlawful means and

conspiracy by lawful means.140 A conspiracy by unlawful means is constitute
when two or more persons combine to commit an unlawful act with the
intention of harming the plaintiffs economic interests.141 In a conspiracy
by lawful means, there need not be an unlawful act committed by th
conspirators. However, the additional element that needs to be proved i
that it was the predominant purpose of all the conspirators142 to cause injury
to the plaintiff; it is now clear that this is a requirement peculiar to conspiracy
by lawful means and does not apply in the case of a conspiracy by unlawful
means.143
With respect to conspiracy by unlawful means, the unlawful act concerned
may be any act contrary to the civil or criminal law. Thus, wrongs such

140 This division is well-established, having been accepted by the House of Lords in decisions
such as Crofter Hand-Woven Harris Tweed Co Ltd v Veitch, supra, note 17; Lonrho Ltd
v Shell Petroleum Co Ltd, supra, note 35; Lonrho pic v Fayed, supra, note 35. The distinction
was accepted by Chao J in Multi-Pak Singapore Pte Ltd v Intraco [ 1994] 2 SLR 282, reversed
without affecting this point at [1995] 1 SLR 313. See, however, Tuan Haji Ishak bin Ismail
v Leong Hup Holdings Bhd [1996] 1 MLJ 661 at 699D.
141 Ibid.
142 It is not enough that only one member of the conspiracy is acting with such a predominant
intention: McKernan v Fraser, supra, note 32.
143 Lonrho pic v Fayed, supra, note 35; Sim Leng Chua v Interfood Ltd Suits No 4049, 4050
of 1982 (Coomaraswamy J, Singapore Hgih Court, 22 September 1992, unreported); Seagate
Technology (S) Pte Ltd v Heng Eng Li [1994] 1 SLR 534, the High Court's decision on
the conspiracy action affirmed by the Court of Appeal at [1995] 1 SLR 17. Prior to the
Lonrho decision, the law in England was unsettled due to the ambiguity in the speech of
Lord Diplock in Lonrho Ltd v Shell Petroleum Co Ltd (No 2), supra, note 35, at 188-189.
It was thought that the requirement of a predominant purpose to injure also applied in a
conspiracy by unlawful means: Allied Arab Bank Ltd v Hajjar (No 2) [1988] 1 QB 944;
Metall und Rohstoff AF v Donaldson Lufkin & Jenrette Inc, supra, note 89; Dellabarca
v Northern Storemen and Packers Union, supra, note 75; The Wing On Bank Ltd v Wai
Man Estates [1990] 1 HKLR 375; Certact Pte Ltd v Tang Siew Choy Suit No 451 of 1991
(Chao J, Singapore High Court, 3 March 1991, unreported). This created a furore among
commentators: see, eg, Eekelaar, The Conspiracy Tangle (1990) 106LQR223; Carty, supra,
note 1, at 253; Sales, supra, note 56. The Australian and Canadian courts consistently took
the view that a predominant intention to injure is required only in a conspiracy by lawful
means: Williams v Hursey, supra, note 127; Canada Cement LaFarge v BC Lightweight
• Ltd (1983) 145 DLR (3d) 385.

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SJLS A Perspective on the Economic Torts 511

as defamation,144 fraud143 and a breach of a statute146 woul

means for the purposes of the tort.

2. Predominant purpose

A conspirator does not act with the predominant purpo

plaintiff if he acts only to protect or further his own
will not be liable for conspiring to protect or furthe
interests or the interests of an association of which he is a member.147
Apparently it may even be enough that the conspirator is advancing a
policy which he bona fide believes in,148 though in such a situation the
general public interest in pursuing such a policy will probably become
relevant to the court's determination. Such an approach has effectively
resulted in the test of predominant purpose being equivalent to asking
whether the defendant is actuated by malice against the plaintiff. It has
been said that the purpose of the combination must be spiteful and malicious145
or actuated by 'disinterested malevolence'.150 The defendants' actions must
therefore serve no commercial purpose of their own.151
However, there are instances where the predominant purpose approach
is possibly inadequate. In the American case of Evenson v Spaulding,152
the conspirators were held liable when they arranged for their men to
persistently trail a rival trader's salesmen and interfere with their efforts
to sell their products. While it could be said that the conspirators were acting
in their self-interest and not with the predominant purpose of injuring the
plaintiff, it is equally clear that their mode of securing their own interests
was unacceptable.
If by adopting the predominant purpose test the courts are declining to
undertake the task of balancing the legitimate commercial interests of the

144 This was assumed in Mrs Kok Wee Kiat v Kuala Lumpur Stock Exchange Bhd [1979] 1
MLJ 71.

143 Seagate Technology (S) Pte Ltd v Heng Eng Li [1994] 1 SLR 534, [1995] 1 SLR 17; Ching
Mun Fong v Peng Ann Realty Pte Ltd [1995] 2 SLR 541.
i46 Multi-Pak Singapore Pte Ltd v Intraco, supra, note 140.
l4. See the excellent discussion in Heydon, supra, note 78, at 150-161.
143 Scala Ballroom (Wolverhampton) Ltd v Radclijfe [1958] 1 WLR 1057.
149 Lord Buckmaster, Sorrell v Smith, supra, note 6, at 748. See also Evatt J, McKernan v
Fraser, supra, note 32, at 390-409.
150 Evatt J, McKernan v Fraser, supra, note 32, at 398, following the phraseology adopted
in the American cases of American Bank & Trust Co v Federal Reserve Bank (1921) 256
US 350 and Nann v Raimist (1931) 255 NY 307.
131 Cases where a predominant purpose to injure has been established are not common: see,
eg, Huntley v Thornton [ 1957] 1 WLR 321 ; Hughes v Northern Coal-Mine Workers ' Industrial
Union of Workers [1936] NZLR 781 at 787; X Pte Ltd v CDE, supra, note 35.
152 150 F 517 (1907).

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 512 Singapore Journal of Legal Studies [1996]

respective parties and wider societal interests, then it

be too narrow in an exceptional situation such as th
Evenson v Spaulding. There may be a situation in w
further the conspirators' self-interest should not b
because of the use of questionable tactics, prejudice to
or simply blatant unfairness to the victim. On the oth
that the predominant purpose test is sufficiently flexi
cases but, even so, this will probably entail some lin
is submitted that, ultimately, a wider general test of a
or justification is more appropriate, and the existen
purpose to injure is an instance of when such cau
absent.153 Conduct which is not spiteful but which pa
what is permissible in the name of free but fair comp
ertheless negate the existence of lawful cause of ju

3. The magic in plurality fallacy

Conspiracy by lawful means has been often been tre

as it is not easy to explain why an act which is not ac
by one person becomes actionable where it is comm
agreement between that person and another.154 T
combination may make oppressive or dangerous that w
only from a single person would be otherwise155 igno
modern world of huge business corporations.156 As Pol
question of whether there is magic in plurality will n
some powerful corporation does some of the things whi
one person may do with impunity but two or more m
In truth, of course, the continued existence of the to
lawful means poses a direct challenge to the correctne
The element of combination, which quite clearly shou
added onto the tort to make it formally distingu
troublesome case. In substance, they are fundamentally
conspiracy by lawful means should not be a tort or Alle
One thus waits with bated breath for the appropriate

153
See Salmond & Heuston on the Law of Torts, supra, note 2, at 369.
154 Lord Diplock, Lonrho Ltd v Shell Petroleum Co Ltd (No 2), supra, note 35, at 188; Lord
Bridge, Lonrho pic v Fayed, supra, note 35, at 307-309. This sentiment was echoed by
Judith Prakash JC (as she then was) in X Pte Ltd v CDE, supra, note 35.
155 Bowen LJ, Mogul SS Co v McGregor, Gow & Co (1889) 23 QBD 598 at 616.
156 Lord Diplock, Lonrho Ltd v Shell Petroleum Co Ltd (No 2), supra, note 35, at 189.
157 (1925 ) 41 LQR 369.
158 Heydon, supra, note 2, at 28.

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SJLS A Perspective on the Economic Torts 513

arrive when the courts have to decide to adopt one st

has been the theme of this article, it is hoped that
demise of Allen v Flood and the embracing of a gener
for intentionally-caused harm without lawful cause

4. Justification

Since a predominant intention of the defendant to

has to be established by the plaintiff before there can
be that justification is not a defence to conspiracy b
such a predominant intention is established, it is no
plea of justification may succeed. Moreover, the arg
the availability of justification in respect of unlawfu
here. However, even so, it is suggested that one s
to lay down a rule that justification may never appl
case where it is the equally malicious conduct of the
prompted the retaliation from the defendant, it ma
defendant to plead justification, at least to partia
liability. It would take a truly exceptional case fo
be justified, but this does not warrant any rule that it
of being justified.
With respect to conspiracy by unlawful means,
justification does not apply.161 This position pr
considered. As argued above, unlawful acts are capab
Further, the availability of justification as a de
indicates that it should similarly be a defence to con
means.

VI. Unlawful Interference With Trade or Business

1. General principles

It is a tort for a person to use unlawful means to intentionally interfe

with the trade or business of another person.162 This tort, however, is s

159 See Heydon, supra, note 2, at 28 and 128-132.

160 The burden is on the plaintiff: Lords Wright and Porter, Crofter Hand-Woven Harris Tw
Co Ltd v Veitch, supra, note 17, at 471 and 495 respectively; Huntley v Thornton [19
1 WLR 321.

161 Menzies J, Williams v Hursey, supra, note 127, at 124; Dellabarca v Northern Storemen
and Packers Union, supra, note 75, at 754-755. See also Markesinis & Deakin, supra, note
2, at 397.
162 Fairbairn, Wright & Co v Levin & Co (1914) 34 NZLR 1; Sorrell v Smith, supra, note
6, at 719; Torquay Hotel Co Ltd v Cousins, supra, note 48. at 139; Sid Ross Agency Pty

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514 Singapore Journal of Legal Studies [19961

in its infancy. In particular, the type of intention and u

have not been conclusively decided. Further, there ar
the relationship of this tort with the other economic

2. A general basis for the economic torts?

It is often said that in Merkur Island Shipping Corpo

Lord Diplock expressed the view that the tort of inte
by unlawful means is a genus tort of which interfer
and even conspiracy (without differentiating between
means and conspiracy by unlawful means)165 are
terpretation is probably an unduly wide reading o
if the context in which Lord Diplock's comments wer
The Merkur case involved an action by shipowners
in respect of the latter's acts in causing its members to
of employment (not entered into with the shipowners) an
certain operations for the shipowners' ship, whereupo
rendered in breach of a charterparty. The shipowners s
officials of the union in respect of loss caused by
their performance of the charterparty. This was an ind
the shipowners' business and, on the orthodox view,
means had to be established. The unlawful means reli
was the inducement by the union of the breaches of th
of employment. While this was a totally independent

Ltd v Actors and Announcers Equity Association of Australia

Emms v Brad Jjjvelt Limited [ 1973 ] 1 NZLR282; Gershmanv Man
Marketing Board, supra, note 67; Volkswagen Canada Ltd v
42; Merkur Island Shipping Corporation v Laughton, supra, note
Chocolates Ltd v Aulsebrooks Ltd [1984] 1 NZLR 354; Lonrho
479; Ansett Transport Industries ( Operations) Pty Ltd v Australia
supra, note 30. See also yr Stratford & Son Ltd v Lindley, supr
Acrow (Automation) Ltd v Rex Chainbelt Inc, supra, note 62.
103 Supra, note 39, at 609-610. See also Lonrho pic v Fayed, supra,
Dillon LJ appeared to assume that 'injury by wrongful interfer
contract with the victim' was a case of unlawful interference with trade or business See
also Gibson LJ, ibid, at 491.
164 Beldam LJ, Law Debenture Trust Corp v Ural Caspian Oil Corp Ltd, supra, note 57. at
1233. See also Clerk & Lindsell on Torts, supra, note 2, at para 23-57; Salmond & Heuston
on the Law of Torts, supra, note 2, at 356; Balkin & Davis, supra, note 2, at 665; Carty,
Unlawful Interference With Trade (1983) 3 LS 193 at 203; Carty. supra, note 1, at 250;
Bentil, Improper Interference With Another's Business Or Trade As A Tort [ 1993] JBL 519
at 521-522 and 527.

165 Trindade & Cane, supra, note 2, at 233.

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SJLS A Perspective on the Economic Torts 515

did not give rise to any cause of action on the part of th

the union, its unlawfulness coupled with the fact that it in
trade and business sufficed to constitute the tort of unlawful interference
with trade. It was with reference to these facts that Lord Diplock stated:

... the evidence establishes a prima facie case of the common law tort
... of interfering with the trade or business of another person by doing
unlawful acts. To fall within this genus of torts the unlawful act need
not involve procuring another person to break a subsisting contract
or to interfere with the performance of a subsisting contract... Where,
however, the procuring of another person to break a subsisting contract
is the unlawful act involved,... this is but one species of the wider
genus of tort. (Lord Diplock's emphasis)

Lord Diplock was thus simply referring to the various types of unlawful
conduct which would found liability in respect of the tort of unlawful
interference with trade or business. It is a particular species of this tort
if the unlawful act relied on is an actionable interference with contract,
but other types of unlawful acts may also suffice, that is, other species
may also exist. There is a world of difference between this proposition and
the proposition that an actionable interference with contract is per se a
species of the tort of unlawful interference with trade or business.
Indeed, it would be curious if Lord Diplock was creating a general basis
of liability for the economic torts. It must always be kept in mind that the
term 'unlawful interference with trade or business' is convenient shorthand
for 'interference with trade or business by unlawful means' and not 'in
terference with trade or business which is tortious'. Otherwise the expression
would lose all meaningful content and be relegated to a mere label. If the
orthodox interpretation of Lord Diplock's remarks were to be accepted,
the continued existence of the tort of conspiracy by lawful means would
be a stark and anomalous exception to the principle, since by definition
no unlawful means are involved.166 The same point may be made with
respect to the tort of interference with contract. In cases of direct interference
with contract at least, the defendant's act of interference may be, and in
many cases is, perfectly lawful; it is only when such act is combined with
the other elements of the tort, such as intention, loss and absence of justification,

166 See Balkin & Davis, supra, note 2, at 666-667. As pointed by the learned authors, it is
significant that Lord Diplock, when considering the tort of conspiracy in Lonrho Ltd v Shell
Petroleum Co Ltd (No 2), supra, note 35, did not assert that it was a species of the genus
tort of unlawful interference with trade or business.

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516 Singapore Journal of Legal Studies [1996]

that the overall result becomes tortious and unlawful. The breach of contract
itself is the consequence of the defendant's conduct and should not be treated
as the unlawful means employed by the defendant. The tort of interference
with contract should therefore be correctly classified as a case where loss
is caused by means intrinsically lawful.167 In any event, even if the breach
of contract itself may be regarded as unlawful means, the fact is that there
need not be a breach of contract for there to be an interference with contract.
The conclusion is that the tort of unlawful interference cannot be, and
was not intended by Lord Diplock to be, a general principle of liability
in respect of all the economic torts. The exact nature of the relationship
between these torts, however, bears closer examination.

3. Relationship with the other economic torts

As suggested above, the torts of direct interference with contract and

conspiracy by lawful means are not part of the genus tort of unlawful
interference with trade or business. The tort of conspiracy by unlawful
means should, in contrast, be treated as a species of such genus tort; indeed,
apart from the element of combination, there is no substantive difference
between the two torts. The tort of conspiracy by unlawful means only serves
to highlight the uncontroversial fact that liability for the tort of unlawful
interference with trade or business extends to acts done by a combination
of persons.
The similarity is even more striking with respect to intimidation. A
distinct feature of intimidation appears to be the presence of a threat to
do an unlawful act but, surely, there is no difference between threatening
to do such an act and actually doing it.168 If it is a tort for the defendant
to threaten a third party with a breach of contract unless such third party
takes a course of action which injures the plaintiff, it must equally be a
tort for the defendant to breach a contract with a third party with the intention
of harming the interests of the plaintiff. The fact that a threat was made
simply serves as cogent evidence of the defendant's intention to harm the
plaintiff. On this analysis, there is some doubt whether intimidation should
be seen even as a distinct species of the tort of unlawful interference with
trade or business; it may possess no distinctive characteristics to justify
it being treated so.

167 It is so classified in Heydon, supra, note 2, at Ch 2.

168 See Lord Devlin in Rookes v Barnard, supra, note 6, at 1168.

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 SJLS A Perspective on the Economic Torts 517

4. Intention

It is unsettled what type of intention the defendant must possess in order

to be liable for the tort of unlawful interference with trade or business.
It is clear, however, that it is insufficient that the defendant knew that the
plaintiffs economic loss was a necessary consequence of his unlawful acts.
In the controversial case of Beaudesert Shire Council v Smith,169 the plaintiff
who was licensed to obtain water from a river suffered damage when the
defendant altered the flow of the river by taking gravel from its bed in
breach of a statutory prohibition. Even though there was no intention on
the part of the defendant to harm the plaintiff, the High Court of Australia
held him liable for the plaintiffs loss. The High Court based its decision
on the principle that a defendant was liable for the harm caused to a plaintiff
if such harm was the inevitable consequence of the defendant's deliberate,
unlawful and positive act, even though such act was not directed at the
plaintiff. The Beaudesert rule was subsequently rejected in England170 and
New Zealand,171 criticised by academics,172 and ostracised in Australia
itself.173 It is not surprising, therefore, that Beaudesert was recently overruled
by a full bench of seven judges of the High Court of Australia174 in Northern
Territory of Australia v Mengel,175 In this case, officials of a government
department imposed restrictions on the movement of the plaintiffs' cattle
in an effort to eradicate certain diseases, in the erroneous belief that they
were authorised by statute to do so. They knew that this would cause the
plaintiffs to suffer losses as the cattle would not be capable of being sold
as planned, but they did not intend to harm the plaintiffs. The lower courts
allowed the plaintiffs' claim on the Beaudesert principle but this was

169 (1966) CLR 145.

170 Lonrho Ltd v Shell Petroleum Co Ltd (No 2), supra, note 35.
171 Takaro Properties Ltd v Rowling [1978] 2 NZLR 314 at 339; Van Camp Chocolates Ltd
v Aulsebrooks Ltd, supra, note 162.
172
" See Dworkin and Harari, The Beaudesert Decision - Raising the Ghost of the Action upon
the Case (1967) 40 ALJ 296 and 347; Dworkin, Intentionally Causing Economic Loss -
Beaudesert Shire Council v Smith Revisited (1974) 1 Mon U L Rev 4; Heydon, Economic
Torts (2nd Ed, 1978) at 133-134; Balkin & Davis, Law of Torts (1991) at 687. Cf Sadler,
Whither Beaudesert Shire Council v Smith (1984) 58 ALJ 38.
173
" It was repeatedly distinguished by the Australian courts: see Grand Central Car Park Pty
Ltd v Tivoli Freeholders [1969] VR 62; Kitano v The Commonwealth (1973) 129 CLR 151,
affirmed (1974) 129 CLR 176; Freednuin v Petty [1981] VR 1001; Copyright Agency Ltd
v Haines [1982] 1 NSWLR 182; Dunlop v Woollahra Municipal Council [1982] AC 159.
Cf Hospitals Contribution Fund of Australia v Hunt (1982) 44 ALR 365.
174 This course had earlier been suggested in Elston v Dore (1982) 149 CLR 480 at 492.
175 (1995) 129 ALR 1. See also the recent discussion of this case in Three Rivers District Council
v Bank of England (No 3) [1996] 3 All ER 558.

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518 Singapore Journal of Legal Studies [1996]

reversed in the High Court on the ground that

was not supported by authority176 and that it was d
the boundaries of liability in the torts of negligenc
duty. It could not be subsumed under the tort of u
trade or business since this requires that the un
the person injured,177 whereas there was no such r
Interestingly, there is an early local decision, pred
to the same effect. In Straits Steamship Co Ltd v T
the government had, without statutory authority, exe
from compliance with certain statutory requireme
them to carry on business at a lower cost. Their tr
loss as a result of the unfair competition was held
the government.
While it is clear from the above cases that the unlawful act must be

directed at the plaintiff, it remains unsettled what this means precisely. It

was decided by the English Court of Appeal in Lonrho pic v Fayed179 that,
unlike the case of conspiracy by lawful means, to constitute the tort of
interference with trade by unlawful means no dominant purpose to injure
the plaintiff s economic interests need be shown. Beyond this, there is limited
judicial consideration of the exact state of mind which is required. One
view is that it must be proved that the unlawful act is in some sense directed
against the plaintiff or intended to harm the plaintiff.180 On the other hand,
it may be sufficient if the defendant has deliberately embarked upon a
course of conduct the probable consequences to the plaintiff of which
he appreciated.181 In any event, it seems reasonably clear that a defendant
may not avoid liability by merely showing that he acted with the purpose
of advancing his own interests.182

176 Deane and Brennan JJ thought that it was in fact supportable by old decisions but concluded
that it should be overruled in any event.
177 Reliance was placed on Lonrho pic v Fayed, supra, note 162.
178 (1933) 2 MLJ 43, affirmed, ibid, at 170.
179 Supra, note 162. This was followed in Ansett Transport Industries (Operations) Pty Ltd
v Australia Federation of Air Pilots, supra, note 30, where Brooking J declined to follow
dicta to the contrary by Mason J in Kitano v Commonwealth, supra, note 173. at 173-174.
180 Dillon LJ, Lonrho pic v Fayed, supra, note 162. at 489. Ralph Gibson LJ expressly agreed
with this: ibid, at 492.
181 Woolf LJ, Lonrho pic v Fayed, supra, note 162, at 494; Millar v Bassey, supra, note 48.
182 See Fairbairn, Wright & Co v Levin & Co, supra, note 162; Emms v Brad Lovett Limited,
supra, note 162. Note, however, that these cases may have been implicitly disapproved in
Van Camp Chocolates Ltd v Aulsebrooks Ltd, supra, note 162, at 360.

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SJLS A Perspective on the Economic Torts 519

A somewhat higher standard was adopted by the N

of Appeal in Van Camp Chocolates Ltd v Aulsebroo
plaintiff, who carried on a manufacturing business, suffe
and damage to trade reputation by reason of the defenda
confidential information in breach of his duty to a third
licensor) to manufacture similar but inferior products. T
the plaintiffs claim on the basis that there was insuffi
part of the defendant to harm the plaintiff. It was opined
intent to harm the plaintiffs economic interests mu
conduct; it must be shown that the defendant would no
the same conduct even without such intent and that the intent alone would

have led him to act as he did. It is not enough that the reasons which actuate
the defendant to use unlawful means are wholly independent of a wish to
interfere with the plaintiffs interests, and such interference is an incidental
consequence foreseen by and gratifying to the defendant.
The common ground between the two approaches is probably that the
defendant must have the plaintiffs interests in his contemplation when he
engages in the unlawful act and must know that his unlawful act would
be detrimental to such interests. The disagreement is over the causative
role of this intent. Put simply, Van Camp Chocolates takes the view that
the defendant's intent must be a 'but-for' cause while the position in Lonrho
v Fayed is that this is not necessary. On balance, it would appear that the
latter approach is preferable as the former imposes a standard which is too
high and which perhaps approaches the level of maliciousness. Such a high
standard is unwarranted where unlawful means have been resorted to. Secondly,
the approach in Lonrho v Fayed would work well with a wide and flexible
defence of justification. The tort would ultimately be better-equipped to
deal with the different factual situations which may arise. The fact that
in a certain case the intent of the defendant to cause injury to the plaintiff
played a greater role in causing the defendant to act as he did would be
relevant in determining whether his acts should be justified. Thirdly, while
the argument that the Lonrho v Fayed approach would entail minute and
refined exploration of the defendant's precise state of mind184 may have
some validity, this is not reason enough not to adopt that test. It is a task
which the courts are already performing in relation to conspiracy by unlawful
means. Indeed, as argued above, conspiracy by unlawful means may actually
be a species of the tort of unlawful interference with trade or business.

183 Supra, note 162, at 360. See also Peter Gibson LJ and Ralph Gibson LJ in Millar v Bassey,
supra, note 47.
184
Van Camp Chocolates Ltd v Aulsebrooks Ltd, supra, note 162, at 360.

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520 Singapore Journal of Legal Studies [1996]

5. Unlawful means

It must be shown that the interference with the pla

was by way of unlawful means. The unlawful mean
causal nexus with the plaintiffs injury.185
It is not entirely clear, however, what is mean
The three possibilities suggested by Carty186 are:
is not at liberty to commit, acts which constitute
which constitute a civil wrong. It is however su
possibility187 is probably no wider than the com
and third possibilities and, on this basis, there is n
not be adopted as the appropriate formula. A breach
held to constitute unlawful means for the purposes
with trade.189
A civil wrong would also constitute unlawful m
representation by the defendant to a third party
loss to the plaintiff may render the defendant lia

185 See Lonrho pic v Fayed, supra, note 162, at 492 and 493
l86Carty, supra, note 1, at 265-273. See also Carty, supra, n
187 This is the formula used by Lord Denning in Torquay Hotel
48, at 139. But 5 years earlier it had appeared in a note by We
v Barnard And The Economic Torts [1964] CLJ 225 at 226.
188 There is some uncertainty as to whether the breach of statute must be one which itself gives
rise to a civil remedy. One view is that it must: see Dillon LJ, Lonrho pic v Fayed, supra,
note 162, at 488, relying on Lonrho Ltd v Shell Petroleum (No 2), supra, note 35, and RCA
v Pollard, supra, note 41. See also Van Camp Chocolates Ltd v Aulsebrooks Ltd, supra,
note 162, at 359. This requirement appears to be based on the perception that otherwise
the tort of unlawful interference with trade or business would circumvent the requirements
of an action for breach of statutory duty. This concern is probably unwarranted, as there
is already the additional element of the defendant intending to inflict harm on the plaintiff.
Furthermore, if the requirement exists then the tort adds nothing to the tort of breach of
statutory duty. The better view is therefore that no such requirement exists: see the tentative
views expressed in Associated British Ports v TGWU [1989] 1 WLR 939 at 952-5, 960
1, 965-6, reversed on appeal without affecting these views, ibid, at 970 et seq. See also
Multi-Pak Singapore Pte Ltd v Intraco. supra, note 140, where Chao J held that on the
alleged facts there was a conspiracy to cause a breach of the statute, without inquiring into
whether such breach gave rise to a civil cause of action.
189 Fairbairn, Wright &Cov Levin & Co, supra, note 162; Emms v Brad Lovett Limited, supra,
note 162.

190 Lonrho pic v Fayed, supra, note 162.

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SJLS A Perspective on the Economic Torts 521

against the plaintiff191 or third parties,192 or, argua

defendant to perform a contract with a third party.193
malicious prosecution against the plaintiff's trade custo
an unauthorised instruction to the plaintiffs bank to
on the plaintiffs banking facilities195 probably constit
Further, in the case where the defendant act is unlaw
party, it is not necessary that the third party suffered
It has been suggested, however, that misuse of confid
in breach of a duty of confidentiality owed not to the
third person is arguably not unlawful means for the p
tortious liability, as any remedy should be given by w
breach-of-confidence principles.197 This is not entirely
to discern any difference between breach of confiden
wrong such as breach of contract and, further, it is at p
as to how breach-of-confidence principles may be
protection on a third party. More fundamentally, the n
means should not be used as a control mechanism; rath
function should be performed by the defendant's inte
plaintiff's interests, provided of course that the meanin
context is properly and precisely defined. Unlawful me
variety of forms and any classification on broad lines s
legal and civil wrongs would probably be arbitrary. Neit
apparent how one would measure the impact or releva
form of unlawfulness in relation to the strength of th
order to effect such classification.
The above analysis is consistent with the notion that the torts of indirect
interference with contract, conspiracy by unlawful means and intimidation
are but species of the genus tort of unlawful interference with trade or
business. Accepting this theory, what suffices as unlawful acts for the
purposes of those species torts would, by definition, suffice for the genus
tort. Unlawful means for indirect interference with contract include diverse

191 Keeble v Hickeringill (1706) 11 East 574n. See also Daishowa Inc v Friends of the Lubicon,
supra, note 17, where the jamming of the telephone lines of the plaintiff pizza parlour on
New Year's Eve to prevent orders being taken was regarded as unlawful; an injunction was
granted to prohibit the defendants from threatening or doing anything that would prevent
the public from placing orders with the plaintiffs customers.
192 Lyons v Williams [1899] 1 Ch 255; Tynan v Balmer [1967] 1 QB 91.
193 Millar v Bassey, supra, note 47.
194 Garrett v Taylor (1620) Cro Jac 567.
195 Volkswagen Canada Ltd v Spicer, supra, note 162.
196 Dillon LJ, Lonrho pic v Fayed, supra, note 162, at 489.
197 Van Camp Chocolates Ltd v Aulsebrooks Ltd, supra, note 162, at 360.

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 522 Singapore Journal of Legal Studies [1996]

unlawful acts such as an inducement of breach of co

representation by the defendant to a third party199
of natural justice.200 With respect to conspiracy by
tort may be constituted where the conspiracy in
defamation,201 fraud202 or a breach of a statute.203
in relation to the tort of intimidation; it is intimidation
a crime, a tort or a breach of contract.

6. Justification

The issue of whether an unlawful act may be ju

with elsewhere in this article. The conclusion being
be justified in appropriate circumstances, the submis
a defence of justification to the tort of unlawful int
or business. This is in line with the suggested pos
is a defence to the torts of conspiracy by unlawful m

VII. Conclusion

The foregoing discussion has attempted to establish five basic points. Firs
it is not too late for the courts to turn their backs on Allen v Flood and
adopt a general principle of liability for intentionally-inflicted economic
damage without lawful cause or justification. Secondly, this should be
accompanied by the introduction of a general defence of justification which
takes into account all the relevant circumstances of a particular case. In
particular, the following factors are relevant: the nature of any right claimed
by the defendant to entitle him to engage in such conduct, the violation
of the plaintiffs legal right, the use of unlawful means by the defendant,
the presence of maliciousness on the part of the defendant and the commercial
unfairness of the defendant's conduct. It is important that this defence
should remain flexible and capable of taking into account all relevant
circumstances. Thirdly, the existing authorities are in any event showing
signs of moving towards this position. In particular, there is recognition

198 DC Thomson & Co Ltd v Deakin, supra, note 49; JT Stratford & Sons Ltd v Lindley, supra,
note 39.

199 National Phonograph Co v Edison-Bell [1908] 1 Ch 335.

200 Posluns v Toronto Stock Exchange, supra, note 77.
201
This was assumed in Mrs Kok Wee Kiat v Kuala Lumpur Stock Exchange Bhd [1979] 1
MLJ 71.

202 See, eg, Seagate Technology (S) Pte Ltd v Heng Eng Li [1994] 1 SLR 534, [1995] 1 SLR
17; Ching Mun Fong v Peng Ann Realty Pte Ltd [1995] 2 SLR 541.
203
Multi-Pak Singapore Pte Ltd v Intraco, supra, note 140.

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SJLS A Perspective on the Economic Torts 523

that maliciously-caused damage to economic expectations may be

actionable and the continued existence of the tort of conspiracy by lawful
means also implicitly challenges the correctness of Allen v Flood. Fourthly,
the above approach facilitates a proper understanding of the relationship
between the economic torts and similar principles of liability in other areas
of the law, chiefly the equitable wrong of knowing implication in breach
of trust or fiduciary duty, the rule in De Mattos v Gibson and the doctrine
of economic duress. Finally, the tort of unlawful interference with trade
or business is not a genus tort in respect of all the economic torts; it is
the genus tort only for the economic torts the essence of which is the use
of unlawful means, that is, intimidation and conspiracy by unlawful acts.
The tort of interference with contractual or other rights is in another category,
since its emphasis is on the violation of a legal right. The tort of conspiracy
by lawful means, on the other hand, bases liability on the malicious conduct
of the defendant and should also be treated separately. The formidable
argument that there cannot be any magic in plurality, coupled with the few
cases recognising that there could be liability for malicious damage to
economic expectations, strongly indicate that it should more rightly be a
tort of malicious damage to economic rights. Such an organisation of the
economic torts accords with the suggested formulation of general principle.

Lee Eng Beng*

LLB (Hons)(NUS); BCL (Oxon); Lecturer, Faculty of Law, National University of Singapore.
Thanks are due to Assoc Prof Tan Keng Feng, Ms Mary Wong and Mrs Ng-Loy Wee Loon
for their valuable comments. 1 remain responsible for all views expressed and all errors
made herein.

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