Senator Martin Mansergh of Fianna Fáil yesterday defended the actions of the Taoiseach and insisted the party had full confidence in his leadership.
He described as "absurd" any notion that Mr Ahern could be influenced by the Manchester payment, adding that the contribution had been "given and accepted in good faith".
Speaking on RTÉ's News at One yesterday, Dr Mansergh who is a former Irish Times columnist, said he "was a little bit surprised" that a newspaper using "anonymous information" had not asked where the information had come from and for what reason.
He also queried if the use by The Irish Times of an academic thesis in 1990, which contained an interview with former tánaiste Brian Lenihan, had been "unethical". Questions of "ethical accountability" must also apply to the media, he said.
In relation to concerns that the Progressive Democrats may now have regarding the future stability of the Coalition, Dr Mansergh said the two parties had enjoyed a "good and loyal partnership" and that any uncertainties had been "exaggerated".
"I don't accept the notion of an unprecedented crisis . . . 10 or 20 years ago these things wouldn't have arisen. The rules have tightened up considerably," Dr Mansergh said.
Asked about the possibility of the PDs withdrawing from Government, Dr Mansergh said he would be very surprised "if at the end of the day they were to walk away from this. That would naturally, however, be their choice."
Dr Mansergh rejected suggestions that Fianna Fáil might have to replace Mr Ahern as leader of the party.
He insisted Fianna Fáil and the PDs had entered Government with each other out of "choice not necessity".