TENSIONS are mounting in the Government over the payment of bonuses in Irish Water, with ministers opposing performance-related pay.
Staff at Irish Water will receive bonuses of up to 10pc of salary, depending on the quality of their performance, the Dail's Public Accounts Committee heard.
In Bord Gais, average bonus payments worth €7,000 have been paid out to its 300 staff.
Mr Tierney said the decision to pay bonuses was done having notified the Department of Communications, and approval was granted for Irish Water to follow Bord Gais' example.
Defending the spend on bonuses, Mr Tierney said the company has moved away from the practice of paying increments and a pay freeze is in place until 2016.
Mr Hogan also rejected claims that he should have personally checked how the €180m worth of Irish Water funding was being spent.
Taoiseach Enda Kenny said Mr Hogan will not be asked to resign over the Irish Water controversy following revelations of the €86m expenditure on consultants.
Standing firmly by the Environment Minister, Mr Kenny rejected suggestions that the semi-state company has been shrouded in secrecy.
Department of the Environment secretary general Geraldine Tallon said it was not the case that Mr Hogan knew nothing.
"Our minister knew the broad figure in December 2012," she said.
"He was involved in the assessment of the NPRF loan. Our minister received a submission from us and sought agreement from other ministers, finance, per and communications over the loan," she added.
But Ms Tallon said she did not mention the €50m spend on consultants to her minister.
"I didn't speak to the minister in specific terms about that figure. The minister was aware of the €180m overall. Minister was aware of how those costs broke down. He knew the majority of the spending was to do with the set-up costs," she told the committee.
"We had regular monthly and quarterly expenditure reports under the various lots. We didn't interrogate it as to what was internal or external. We were more concerned that the spend stay within the envelope," she added.
Ministers expressed discomfort at the talk of bonus payments.
Mr Hayes said Mr Howlin had eliminated the payment of bonuses in the semi-state sector.
Ms Burton also signalled her opposition to the payment of bonuses, saying she "didn't see it as appropriate".