A consultant based at University Hospital Waterford has said the proposed increase in services at the cardiac catheterisation lab suggested in an independent clinical review is "inadequate" and based on incorrect population figures.
Dr Patrick Owens said the issue should be revisited by the Government in consultation with local consultants and Dr Herity.
Speaking on RTÉ’s News at One, Dr Owens said that because of the existing delays in accessing the service, patients from around the south east are transferred elsewhere.
Dr Owens said this indirectly lowers the figures measured in the report.
"If you under-invest in the cath lab it becomes unable to cope with relevant demand and patients are referred elsewhere which makes the population seem lower," said Dr Owens.
He said downgrading the service based on that conclusion would be wrong.
However, the consultant who carried out the review has defended his belief that a second specialised laboratory is not justified.
Speaking on RTÉ's Morning Ireland, Dr Niall Herity said he recommended "quite a substantial expansion" of services at the existing facility.
Provision of a second catheterisation laboratory is at the centre of a dispute between the Government and John Halligan, a Minister of State and local Waterford TD.
Mr Halligan believes that a second cath lab is needed but this has not been recommended in the review, which was commissioned by Minister for Health Simon Harris in May.
Mr Halligan has claimed a HSE briefing document for Dr Herity, seen by RTÉ's Prime Time, reveals there was "gross interference" with the independent review.
However, Dr Herity stressed he had no conflict of interest and carried out his work in an objective, dispassionate and independent manner.
Dr Herity, a consultant cardiologist with the Belfast Hospital Trust, said that while his review found there was no need for a second lab, the hospital was under-resourced and should increase the four-hour sessions at the lab from 10 to 12 per week.
He said the vast majority of work in cardiac cath labs is planned work. Only 4% in UHW is emergency work, he added.
Dr Herity said he measured the unit's catchment population at 286,147, a figure disputed as too low by consultants at the hospital and by Mr Halligan.
Minister for Social Protection Leo Varadkar has said Mr Harris dealt with the issue correctly by appointing a consultant from outside the State to conduct the report.
Speaking in Cork this afternoon, he said he hoped Mr Halligan would remain in Government.
Issue with communication in Govt - Naughten
Meanwhile Minister for Communication, Climate Action and Environment Denis Naughten has said there is an issue with communication in Government.
He said it was up to all involved to work together, to try and improve the level of communication between Fine Gael and independent members.
He said he hoped TD's on all sides of the house could be kept abreast of developments, so that informed discussions could take place .
Speaking in Co Galway, the minister said there was no doubt that the Government had faced challenging issues in recent weeks.
He said it was certain there would be similar problems in the future, but that there was an onus on all TDs to work with each other and come up with solutions that were "practical and implementable".
Mr Naughten said this was not an easy task but this was the challenge faced by parliamentarians, given the result of last February's election.
Asked about the row over the provision of services at Waterford University Hospital, Minister Naughten said he felt Mr Halligan needed to look at the issues surrounding the hospital "in totality".
He said there was an opportunity to improve the quality of services being provided to people in the region, not just in relation to the improvement of the cath lab there but also to establish a second air ambulance service in the southern half of the country.
Minister Naughten said such an extension of the air service would mean that people with heart attacks, strokes or serious brain injuries could get treatment in specialist centres in a timely manner.
He said he felt Mr Halligan should stay the course and remain in Government, because he said his input was important.