Senior Labour TD Alan Kelly has said he voted against his party backing Independent TD Catherine Connolly for the presidency and will not be supporting her in the upcoming election.
Speaking on Tipp FM, Mr Kelly asserted there was "a large cohort" within Labour of the same view.
He said he was particularly concerned at Ms Connolly's views on international affairs regarding Syria, Russia and her statement that she was ashamed of the EU, as well as recent comments in relation to the US and France.
The Tipperary TD also cited "her association with the likes of Mick Wallace", who will be "helping her".
Referencing Ms Connolly's criticism of Labour in recent years and her accusation that the party has "lost its soul", Mr Kelly said: "To be honest with you, the manner in which she has treated us, I think, you know, as a party, we have to have a level of self-respect."
Mr Kelly added there was another "fundamental issue" as to why he would not back her campaign, which was "probably the biggest issue for me".
He added: "Seven years ago, Catherine Connolly believed that supporting Gemma O'Doherty, and nominating her, was a better option than supporting Michael D Higgins."
"He's been an exceptional President, an incredible human being, a very brave person, and I don't think it's possible for many people the Labour Party, in all conscience and with self-respect, to support presidential candidate who, seven years ago, who thought of backing Gemma O'Doherty."
A Labour spokesperson said: "At the end of July, after an extensive consultation with party members, the Parliamentary Labour Party and Executive Board democratically decided to endorse the Catherine Connolly campaign for president, as recommended by the majority of members."
Responding to Mr Kelly's comments, Ms Connolly said she was grateful for Labour's support and that of the Social Democrats, People Before Profit and independents who have "weighed in" behind her campaign.
The Independent candidate said it was heartening to see those on the left coming together to achieve their common goal of putting a progressive and unifying voice in Áras an Uachtaráin, and she was beyond proud to have their backing.
She said this cohesion indicates a bright future for Irish politics.
Ms Connolly also said she is hopeful she could win the support of Sinn Féin, but said that if Sinn Féin does field a candidate, such as its leader Mary Lou McDonald, it would not be "curtains" for her campaign.
Speaking on Virgin Media News, Ms Connolly criticised Fianna Fáil and Fine Gael's perceived "delay" in choosing their election nominee.
"I must say, the delay in choosing a candidate by the bigger parties says a lot about their approach to a very important role, protected by the constitution, set out in the constitution.
"So in that sense, the delay and the rhetoric around who they will pick and a Lanigan’s ball type approach, is disrespectful."
She added that Sinn Féin have said "from day one" that they would "make up their mind" in September, and that it was "not helpful" that Fianna Fáil had not yet set out their position.
Jim Gavin would be a 'fine' Fianna Fáil presidential candidate, says minister
A senior Fianna Fáil minister has said that former Dublin football manager Jim Gavin would make a fine Presidential Election candidate.
Minister for Further and Higher Education James Lawless said that values such as being pro-Europe, community cohesion and social justice would have to be reflected by any potential Fianna Fáil candidate.
"In terms of Jim Gavin, as with many others, there are a number of names being speculated on - I think he would be a fine candidate; there are other equally fine individuals being suggested, all of whom have merits," he said.
Mr Lawless said that while it is not certain yet that his party will field a candidate, that is the "direction of travel".
The Kildare North TD said the Fianna Fáil parliamentary party would deliberate on this matter in the next couple of weeks.
Mr Lawless, who is also an honorary Fianna Fáil secretary, would not be drawn on whether the party should select an internal candidate or someone from outside its ranks.
Read more: Who are the potential runners and riders in the race for the Áras?
