Clondalkin councillor Therese Ridge, who faced disciplinary proceedings from Fine Gael following adverse findings in the Mahon Report, has resigned from the party.
Ms Ridge lost the party whip after a party disciplinary committee had ruled she had seriously damaged the interests of Fine Gael by accepting money from lobbyist Frank Dunlop.
She had said she would be appealing the finding, but today announced she was dropping the appeal and leaving the party, saying she could not get fair procedures.
Ms Ridge included a newspaper cutting that quoted party leader Enda Kenny as saying he accepted the disciplinary findings against her.
She said: "I see little point in proceeding with such an appeal because clearly no fair procedures could apply in such a case.
"Any element of fair procedures has been severely curtailed because of the public acceptance of the findings of the Disciplinary Committee by the President of Fine Gael."
The Fine Gael inquiry was prompted by the finding of the Mahon Tribunal that she acted "entirely improperly" by accepting a donation of £1,000 in cash from Frank Dunlop during the 1992 General Eleciton.
At the tribunal, she denied testimony from Mr Dunlop that she asked him to make a donation to her colleague Olivia Mitchell.
Ms Mitchell has been exonerated by the party's disciplinary committee though the tribunal found she received an "inappropiate" donation of £500.
Ms Ridge was also required to resign from all committees associated with a her role as public representative, which included Chair of the South Dublin Transport committee and member of Dublin County VEC.
This had been put on hold pending the appeal.
Ms Ridge could continue serving as an independent councillor.