Taoiseach Enda Kenny has said he takes full responsibility and the blame for the controversy surrounding the nomination of John McNulty for the Seanad.
Speaking in Roscommon this afternoon, Mr Kenny said what happened was of his own making but would never happen again.
He said he regretted his decision and Minister for Arts, Heritage and the Gaeltacht Heather Humphreys was not in any way to blame for what had happened.
Mr Kenny also denied claims that fear stalked the corridors of Fine Gael in the way it did in Fianna Fáil during the reign of Charles Haughey.
Taoiseach admits he is to blame for John McNulty controversy https://t.co/rIenlPzyap— RTÉ News (@rtenews) September 26, 2014
He said nothing of the sort could be compared to the Fine Gael Parliamentary Party where, he said, people were entitled to stand up and criticise him, as they had done on this occasion.
Asked if he would consider a request to be put to Mr McNulty to reassess his candidature, Mr Kenny said he was advised that a legal process was now in place and the nomination would go ahead.
Responding to Mr Kenny's comments, Fianna Fáil Leader Micheál Martin said his statement led to "a number of questions, the most obvious of which is, what exactly is he apologising for?
"Is the Taoiseach now admitting that he instructed Minister Heather Humphreys to appoint Mr McNulty in support of his Seanad candidacy?" Mr Martin asked.
"This goes to the heart of the scandal and requires a full statement in Dáil Éireann from the Taoiseach outlining the entire sequence of events from the beginning to the end of this shabby affair."
Mr Martin also called on Mr Kenny to apologise to the board of IMMA and the membership and staff of Seanad Éireann.
He said Mr Kenny had undermined both organisations with his handling of the matter.
Fine Gael TD Sean Conlan said that Mr Kenny's remarks this evening have made matters worse.
Speaking on RTÉ's Six One, Mr Conlan said Mr Kenny's comments contradict his version of events outlined yesterday.
Mr Conlan called on Minister Humphreys to make a statement to explain herself in connection with the issue.
Earlier, he said there was a fear within the party that the Taoiseach was returning to the "days of stroke politics" and "the days of Charlie Haughey".
Speaking on RTÉ's Today with Sean O'Rourke, the Cavan Monaghan TD said the vast majority of Fine Gael TDs want to see reform in Irish politics.
Mr Conlan also said Fine Gael TDs did have a fear of speaking out and this needed to end.
He said the appointment process should be transparent and he believed Mr McNulty had been damaged by the way he was appointed to the board.
Mr Conlan said the appointment process is flawed and both the minister's and the Taoiseach's actions had damaged Fine Gael.
Call for McNulty to withdraw from race
Fine Gael Senator Cáit Keane has said Mr McNulty would be "doing himself a great service" in reconsidering running for the Seanad.
Senator Keane made her comments yesterday to Newstalk while canvassing for the Dublin South West by-election.
She said the controversy surrounding Mr McNulty was having a damaging effect on the Fine Gael party.
Mr McNulty announced his resignation from the Irish Museum of Modern Art board yesterday following a wave of criticism in relation to the appointment.
The Opposition had said the appointment was made to help the candidacy of the Donegal businessman in the forthcoming Seanad by-election.
Earlier, Minister for Finance Michael Noonan had sought to play down the controversy surrounding the appointment of Mr McNulty to the IMMA board this afternoon.
Speaking in Limerick, Mr Noonan said Fine Gael was a very big party across both the Dáil and Seanad and that there were bound to be differences of opinion on matters.
He said he has never been at a parliamentary party meeting in which differences of opinion were not expressed, but he believed it would be sorted out in due course.
Minister Noonan said controversy was in the nature of politics but that the important thing is to work through it as honestly as possible and to keep the party moving in the same direction.
McNulty appointment is defended
Fine Gael TD for Mayo Michelle Mulherin defended the appointment of Mr McNulty to the board of IMMA.
Ms Mulherin, speaking on RTÉ's News At One, also defended the Taoiseach on his appointment of women to the Seanad.
She said: "The Taoiseach has to decide, at any given time, who is the best person.
"Gender is a consideration, there are other considerations, the ultimate adjudicator on that is the Taoiseach, but suddenly the Taoiseach's ability to decide who is the best candidate and where they should be is called into question, when all his nominees - who are independent, excellent senators - nobody has called into question his judgement in relation to them, why now?"
Sinn Féin's Vice-President Mary Lou McDonald echoed Mr Conlan's comments, saying the prudent and honourable thing to do would be for Mr McNulty to withdraw from the election.
Ms McDonald called on the Taoiseach and Minister Humphreys to give a full account in the Dáil of how Mr McNulty came to be appointed to the board of IMMA.
She also said her party had been told it was not possible within the rules to re-run the Seanad by-election.