Equality Minister Aodhán Ó Ríordáin insisted Fine Gael had let its side of the Coalition down and helped deepen the Government’s unpopularity.

“People are frustrated with the Government and we have had a very bad year — none of it, I would say, caused by Labour ministers,” he told the Irish Examiner.

He said Labour had to try and “keep things afloat” because some Fine Gael ministers had not done a good enough job.

The row threatened to overshadow a concerted Coalition attempt to relaunch the Government after a disastrous year which saw it lurch from one controversy to another.

Asked if he thought Fine Gael had let the side down, Mr Ó Ríordáin said: “Yes I do,” adding that a lot of the problems over the last 12 months “emanated from ministers who should have done better” in their roles.

He singled out former justice minister Alan Shatter and former environment minister Phil Hogan as centres of concern, but said the performance of those departments had improved significantly since both men had left the Government.

“We have worked very hard on the Labour side to keep things afloat and keep us focused,” he said.

The attack drew a stinging response from the Fine Gael chief whip Paul Kehoe, who said a “blame game” culture would not help the Government.

“I’m in a government with Fine Gael and Labour,” he said. “This is about collective responsibility.

“If there was a Labour minister or Fine Gael minister and I felt they were doing something wrong I would stand up and say it at the Cabinet. The blame game, I think that’s petty, trying to score own goals, this is about collective responsibility.”

He insisted Mr Ó Ríordáin would have had plenty of opportunities to air his concerns.

“Junior ministers have opportunities to be able to raise and question other ministers,” he said. “I believe if he thought that there are opportunities he could have gone and spoke to the Tánaiste or Taoiseach.

“I’m not into blame games, this is about collective responsibility and being together. There is plenty of platforms for a minister to criticise another minister from the Government without going to the media.”

Poll ratings for both parties have slumped after 12 months of controversy as the Government tried to get a grip on problems ranging from the setting up of Irish Water, to the whistleblower affair, the GSOC bugging incident, the withdrawal of medical cards, and the Cronygate storm surrounding the nomination of John McNulty to the Seanad.

Mr Kehoe has admitted the Government behaved in an “underhand” way during the cronygate controversy which caused deep annoyance among Labour TDs.

Tensions have also been sparked in the Coalition over how to deal with the Universal Social Charge as Labour wants to use any windfall from the improving economic situation to target reductions in the levy, while Taoiseach Enda Kenny is keen to prioritise cuts to the top rate of income tax for lower and middle earners.