The Labour Party has lost a second councillor in a week amid fresh criticism of leader Brendan Howlin.
Cllr Mick Duff, who led calls during the summer for Mr Howlin to resign has today walked away from the party.
The party has struggled for relevance since being booted from office in 2016 when it lost 30 seats in the Dáil.
His decision to resign follows that of his fellow Dublin South West councilllor, Martina Genockey, who despite being promoted heavily by Mr Howlin, felt he should stand down.
Responding to the resignation, a Labour spokesperson said: "After the Drogheda think-in there was a great sense of unity in the Party, so we are sad to see any member leave."
"We regret Mick's decision to resign but wish him all the best for the future," the statement said.
In his letter to Mr Howlin and party General Secretary Brian McDowell, seen by the Irish Examiner, Mr Duff said the appointment of Mr Howlin has had a “detrimental effect” on the party.
“Notwithstanding the democratic deficit involved, the decision by Brendan to insist on his not being elected by the membership at a very minimum prevented the catharsis needed for the Party in the wake of what was a very difficult period in government and a bruising election campaign,” he wrote.
He said the party is heading into oblivion like the SDLP in the North.
“We have learned no lessons from our time in Government and seem hellbent on returning to Coalition as soon as we hear the noble call. Difficult as it is in opposition as a small Party, we could effectively use that time to reorganise, rejuvenate and rebuild,” he said.
“Regaining trust as a Party of social conscience is not easy, but it is a road I hoped the Party would travel. Instead, we hear calls for partnering up with the Social Democrats and the Green Party, bringing Labour into a situation like the SDLP, on a road to oblivion,” he wrote.
“Effective immediately, I am resigning from my position as DSW Constituency Council Chairperson, Central Council member and my membership of the Labour Party. I wish all my former Labour Colleagues, past and present the very best for the future. I intend to remain on as a non-party member of the current South Dublin County Council,” he concluded.
A response from Mr Howlin's office has been sought.
Full statement from Cllr Mick Duff