A fourth councillor has resigned from the Green Party.
Dublin-based Peter Kavanagh has stepped away from the Greens, citing internal abuse over his criticism of the party leadership.
Mr Kavanagh said the culture that has emerged in the party since entering Government is not one he can reconcile with his values.
In a series of tweets, he said: "I have never made my opposition to the Programme for Government a secret, having spoken against it at the Special Convention last year.
"Unfortunately, my voicing opposition to Government decisions within the party has been met with a culture I cannot reconcile with the values of the Green Party/Comhaontas Glas.
"I remain committed to serving the people of Clondalkin, Newcastle, Saggart, Rathcoole and Brittas on South Dublin County Council with the support of my former party colleagues".
I've taken the very difficult decision to step down as Urlabhraí na Gaeilge & Gnóthaí Gaeltachta and resign from the Green Party/Comhaontas Glas with immediate effect.
I have never made my opposition to the Programme for Government a secret, having spoken against it... 1/2— Cllr. Peter Kavanagh (@TheKavOfficial) January 25, 2021
He becomes the fourth Green Party councillor to resign in the last seven months.
A former member of the party's executive committee claimed last year that more resignations were "inevitable".
Lorna Bogue had been a vocal critic of the party in Government, and said she has little confidence in Green Party ministers.
Aengus Ó Corráin, who was Ms Bogue's campaign manager in 2016, told Newstalk there were two key reasons for the string of resignations.
He said: "First, I think because there's been a failure of competence, in particular in regard to the communication from the parliamentary party and the Ministers since we've entered Government and I think that's contributed to massive misunderstandings of our first few policy initiatives.
"Second, I think it's happening because the grassroots and the Councillors below the TDs feel they are being ignored and criticisms they have of how the party does business at the highest level is not being listened to.
"I think it's a sense of frustration more than anything else that Lorna has resigned.
"There's a feeling that there's not receptiveness in leadership towards criticisms be they constructive or otherwise", he added.
Reporting by: Sean Defoe and Jack Quann