Taoiseach Enda Kenny has said Phil Hogan will not be asked to resign over the Irish Water controversy.
Mr Kenny stood firmly by his Environment Minister and rejected suggestions that the semi-state company has been shrouded in secrecy.
Fianna Fail leader Mr Martin accused Mr Kenny of "pretending all is well, that all is transparent".
But taking the first 'Leader's Questions' of the new Dail term, Mr Kenny said the investment in Irish Water is being made to ensure the public can access high quality water.
"This is a public utility in public ownership, therefore there is nothing that should be secret about it and there is nothing that will be secret about it'" Mr Kenny told the Dail.
Environment Minister Phil Hogan today said he did not personally know about the massive spend on consultancy by Irish Water.
Mr Hogan strongly defended his handling of the establishment of the semi-state body, insisting: "You can't make an omelette without breaking eggs".
Officials at Irish Water were this evening due to appear in front of The Public Accounts Committee, just 24 hours after they were quizzed by the Oireachtas Environment Committee about the spend on consultancy services.
Speaking at Trinity College this morning, Mr Hogan said he was not personally aware about the sum being spent on consultancy.
"€180m was the overall costs of what was deemed to be appropriate for the establishment of Irish Water. And the detail in relation to what contracts were being given out or who was procuring is not my business, it's a matter for Irish Water."
Asked whether he believed the controversy surrounding Irish Water has become a PR disaster, the Fine Gael minister said:
"Not at all. You can't make an omelette without breaking eggs."
Mr Hogan also rejected suggestions that he should have spoken directly with Irish Water Managing Director John Tierney about the operating costs.
Mr Hogan said he had "no regrets whatsoever" and added that bonuses was an issue for the Department of Public Expenditure.
Meanwhile, the chairman of the Public Accounts Committee has described the secrecy surrounding Irish Water as unacceptable, and has called on the Comptroller and Auditor General to audit the books. .
John McGuinness told RTE Radio that there are significant questions to be asked Irish Water executives who are appearing before the PAC today later today.
He added Mr Hogan needs to micro-manage Irish Water spending, saying it is scandalous that he does not.
By Niall O'Connor, Political Correspondent