Minister for Pubic Expenditure and Reform Jack Chambers has said he deeply regrets the manner of Jim Gavin's withdrawal from the presidential election campaign.
Minister Chambers was Director of Elections for Fianna Fáil in Mr Gavin's campaign.
He said there was "huge" upset and disappointment expressed by TDs, senators and MEPs at a meeting of the Fianna Fáil Parliamentary Party at Leinster House last night,.
He said he was sorry and that lessons would have to be learned for the future.
Minister Chambers was speaking following a charity budget briefing in Kinsale, Co Cork.
When asked if he owed Fianna Fáil supporters an apology as Director of Elections, he said he did his best in the role.
"I said I deeply regret and I am sorry for what's after happening. I always do my best in every role I am given for the party and put the party interest first in the work that I do," he told RTÉ News.
"There is huge upset and disappointment at the fact that Fianna Fáil now doesn't have a presidential candidate. A huge amount of work went into the campaign and I think there is broader upset across the party about that."
Mr Chambers described the mood of last night's five-hour parliamentary party meeting as contrite, open and honest.
"I deeply regret what's after happening. I would much prefer to be out canvassing, mobilising our grassroots and ensuring that Fianna Fail is in the contest," he added.
Mr Gavin withdrew from the election after it was revealed he had 16 years ago failed to refund a tenant more than €3,000 in overpaid rent.
Taoiseach and Fianna Fáil leader Micheál Martin last night apologised to his party colleagues over how the presidential election campaign was handled.
Mr Martin acknowledged the hurt and shock in the party after Mr Gavin withdrew from the contest last Sunday.
He told his party that he was sorry and devastated about the dramatic unravelling of the campaign.
And he said again this week that he intends to lead the party into the next general election.
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FF members treated 'like vegetables', says Ó Fearghaíl
There was no direct challenge at the meeting to Mr Martin's leadership, but former Ceann Comhairle Seán Ó Fearghaíl spoke of the need to fully reform how the party operates by the beginning of 2027.
This was interpreted as a signal that a leadership changeover could come into focus at that point.
Speaking on RTÉ's Morning Ireland, Mr Ó Fearghaíl said Fianna Fáil's parliamentary party are treated like "vegetables" who are "told what to do and what to think".
In a scathing attack on his party, the Kildare South TD said Fianna Fáil needs reform and suggested the future of Mr Martin's leadership could come into focus after Ireland's EU Council presidency ends in December next year.
Mr Ó Fearghaíl said reform is needed in Fianna Fáil so its parliamentary party members are listened to, and that Mr Martin needs to adapt to that change.
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He said Mr Martin's apology "doesn't mean anything for the Taoiseach’s leadership of Fianna Fáil in the short term" but hinted otherwise for the future.
Deputy Ó Fearghaíl's attack came as he explained why he recounted a story about the late Fianna Fáil leader Charles Haughey ordering dinner in a restaurant to make the point that TDs, Senators and MEPs are not listened to from the party's upper echelons and by its leadership.
"There are many stories told about the late great Charles Haughey. One of the stories was that he, on one occasion, took his Cabinet to one of his favourite restaurants and arriving earlier than anybody else, he was welcomed by the maître d', who showed him to his table and gave him the menu.
"Mr Haughey made his selection and at the end of it, the maître d' said 'Mr Haughey … what about the vegetables?' … whereupon Charlie responded, 'well, they'll have the same as I'm having'," Deputy Ó Fearghaíl said.
He added: "My point is that for a period of time, it would appear that the parliamentary party have been the vegetables. We have been told what to do, what to think, and we haven't been taken seriously."
Deputy Ó Fearghaíl also said at the meeting that "the Taoiseach appeared genuinely upset, very anxious to atone for the mistakes that were made".
"He did, I think, connect effectively with the members and did appear to listen to take the messages on board," he said.
"The room, while being full of anger, was also full of goodwill because there was unanimity that number one, Jim Gavin and his family needed to be supported now with the aftermath of the trauma that they've been through. But equally so, Fianna Fáil needs to get over what has been an utter and absolute debacle," he added.
"What has occurred around the presidential selection and the really appalling campaign is a symptom of how we've been doing our business as a political party for some time."
Separately, Cork South West TD Christopher O’Sullivan said there is strong "desire to move on from this" in Fianna Fáil, and that there is not a mood within the party for a change in leadership.
"Judging by the tone of the parliamentary party and speaking to parliamentary party meetings over the course of the last couple of days, there's no desire for a change of leadership," Mr O'Sullivan said.
"A year ago, Micheál Martin did what nobody thought he could do, and that is, we came out of the general election as the biggest party. That's not even 12 months ago. Nothing has changed. Not much has changed, at least," Mr O’Sullivan added.
