Minister for Health James Reilly has rejected suggestions of impropriety over the selection of a site for a primary care centre in his constituency.
Two Labour MEPs have called for the resignation of the Health Minister.
Mr Reilly was commenting after it was revealed that a Fine Gael supporter owns the site in Balbriggan in Dublin.
Mr Reilly has said he had no business connections to the site owner, Seamus Murphy, and he had no role in the choice of the site.
The minister also said the Balbriggan site is in the hands of the National Asset Management Agency and so its development will not even benefit Mr Murphy.
Earlier Minister for Education Ruairi Quinn said the Balbriggan site was selected by Mary Harney when she was minister, however that assertion was later withdrawn in the Dáil chamber as it related to a different site.
In a statement the HSE said a site at Stephenstown had been identified in 2008 but the deal fell through. Mr Murphy's site on the Dublin Road was chosen in September 2011.
Call for Reilly to consider his position
Two MEPs have called for Mr Reilly to consider his position.
Labour MEP for the South Phil Prendergast has said that party members around the country are unhappy and that the minister has become a soap opera in himself.
She said he has not clarified why he chose one area over another for primary care centres.
On Twitter earlier, she said that "this is the sort of politics that has brought us to ruin".
Labour MEP Nessa Childers said on Twitter earlier that she had "grave concerns about his suitability in delivering positive and progressive health care".
Taoiseach Enda Kenny today said the Government has given its "absolute backing" to Mr Reilly.
Speaking in Brussels, he said the minister now has a changed and formidable team in the health area, who will have to implement a massive structural series of changes.
Junior health minister Roisin Shortall resigned last week over Mr Reilly's decision to add locations, including two in his own constituency, to a list of proposed primary healthcare centres.
Credibility of selection process 'in tatters'
Speaking on RTÉ's Morning Ireland, Fianna Fáil finance spokesman Michael McGrath said the credibility of the selection process for locating the centres now lay in tatters.
He said: "We now need to have Minister Reilly come before the House, make a comprehensive statement to the Dáil on the selection criteria that was used and to take questions from the Opposition spokespersons.
"We will be calling on him again today, as we did yesterday, to do that because we are not satisfied with the information that has now come into the public domain.
"It raises fundamental questions that really need to be answered and the entire integrity of the selection process has now been undermined."
Sinn Féin's health spokesman Caoimhghín Ó Caoláin said Mr Reilly "failed to clarify the basis for his selection of locations for primary care centres".
He said: "Public confidence in the minister and in the Government's primary care strategy is at rock bottom."
This morning, Minister for Education Ruairi Quinn defended Minister Reilly in the Dáil.
Mr Quinn said he was quite satisfied that the location of the site in Balbriggan was according to criteria and that the selection was one that the minister had dealt with satisfactorily.
NAMA list of sites
A National Asset Management Agency list of sites to which the agency has appointed receivers does not include the controversial Balbriggan site.
NAMA's website lists a series of properties at Mill Street in Balbriggan as being subject to "enforcement action", meaning receivers have been appointed on foot of debts taken over by the agency.
The Balbriggan site added to the list of primary care centres by Dr Reilly is on nearby Dublin Road.
The appointment of a receiver would give NAMA, rather than the debtor, direct power to develop or sell any site as it deems appropriate.