Fine Gael has confirmed the resignation of one of its councillors, Frank McBrearty, just two months after he joined the party and one week after the local elections.
Mr McBrearty, speaking to RTE radio, said he is to sue his now former party for post-traumatic stress disorder.
Cllr McBrearty alleges he was the victim of bullying and was not welcomed into the party by some elected representatives.
He resigned his membership in a letter to Tom Curran, General Secretary of Fine Gael.
“I am officially resigning from the Fine Gael party due to personal attacks on my family and I by Fine Gael members in Donegal,” he wrote last week.
During the interview, Mr McBrearty said that disagreements over power-sharing arrangements on the council led to very heated discussions within the Fine Gael members of Donegal council.
It was claimed by Mr McBrearty, who previously stood for the Labour Party, that he was offered positions on three national party committees in a bid to try and get him to rethink his decision to resign.
He said he was offered positions on the new Policing Authority, the Loughs Agency, and an unnamed national committee.
Mr McBrearty, now as an independent, said he hopes to be part of a power-sharing agreement in Donegal County Council.
"I have to talk to the independents and the other groupings, Fine Gael included....If I am excluded from power-sharing I will make the council unworkable,” he said.
A spokeswoman for Fine Gael said the party had no comment as to the claims made by Mr McBrearty other than to confirm it had received his letter of resignation.
Mr McBrearty's resignation was greeted with disappointment from local TD and Education Minister Joe McHugh.
“I am disappointed that Frank has resigned. He’s a hard working councillor and I wish him well in his role as a councillor in the time ahead,” he told a Sunday newspaper.
The Donegal Democrat on Sunday reported that McBrearty, who is based in Raphoe, was unhappy following the outcome of last week's election and had felt that the party locally could have achieved a third seat had their candidates worked more closely together.
Mr McBrearty had fought the previous election on an independent platform and his decision to join Fine Gael was something of a surprise in the first place.