A direct conflict of evidence now exists between the Taoiseach, Mr Ahern, and the British-based property developer, Mr Tom Gilmartin, about the number and content of their meetings and conversations in 1989.
Mr Gilmartin says four meetings took place, two of them before witnesses; Mr Ahern can recall only one meeting.
Mr Ahern also says he has no recollection of a telephone conversation in which Mr Gilmartin says he advised him of a £50,000 donation made to Fianna Fail through Mr Padraig Flynn.
Last night in Dublin, Government sources said Mr Flynn should issue a full statement in response to recent developments.
Contacted at his home last night, Mr Gilmartin said he had met Mr Ahern four times during the late 1980s in connection with his Dublin projects. Two of these meetings took place in the Department of Labour and he had met him twice in a pub on the way out to the airport.
There were witnesses to two of the meetings, he said.
At the time, Mr Gilmartin said, he was "being held to ransom and blackmailed for money by senior politicians and by their cohorts". He had been advised to meet Mr Ahern, as minister for labour, because the projects involved the creation of thousands of jobs.
As a result, Mr Ahern had sent a councillor to talk to him about the matter and had promised he would see what could be done.
Asked whether he had told him about the money he had given to Mr Flynn, Mr Gilmartin said when Mr Ahern had suggested a payment be made to the party, he had told him that £50,000 had already been paid through Mr Flynn. "He made no comment to that," he said.
A short note was issued last night by Mr Ahern, following a discussion with the Tanaiste and leader of the Progressive Democrats, Ms Harney.
In it, Mr Ahern said he recalled only one meeting with Mr Gilmartin; that he had arranged for a city councillor to meet him to discuss his plans; and that he had no recollection of any telephone conversation dealing with contributions to the party or Mr Flynn.
The response was immediately rejected as "sketchy and vague" by the Fine Gael leader, Mr John Bruton, who promised to pursue the matter in the Dail on Wednesday. He also challenged the Taoiseach to say whether he believed Mr Flynn should serve out his term as EU Commissioner.
If, as alleged, Mr Flynn had contacted Mr Gilmartin in connection with his statement to the Flood tribunal, such contact was improper, Mr Bruton said, and the Taoiseach should ask Mr Flynn to stand down.
Pressure on the Government to sack Mr Flynn has intensified following the Commissioner's failure to deny persistent reports that he had received £50,000 from Mr Gilmartin in 1989, when he was party treasurer, and that the money had not been lodged to Fianna Fail.
Contacted in Limerick, the Tanaiste described the allegations against Mr Flynn as "very serious". The Labour Party leader, Mr Ruairi Quinn, warned party members that they should prepare for an early general election and said the Government would not go to full term.
The Green Party said if Mr Flynn had misled the public about the donation, he should be removed as Commissioner under Article 160 of the EC Treaty.
Mr John Gormley TD said such action could be taken by the Government through the Council of Ministers and, while unprecedented, would "send the right signal to the Irish and European electorate who are now tired of scandals in Government and Commission circles".
In an interview with RTE, Mr Gilmartin said Mr Flynn "was not the worst of them. His peers are more street-wise. They appoint tribunals. They hide behind tribunals when they are asked a question and they try to undermine the tribunals with their spin-doctors and their cohorts." It is understood the Taoiseach maintains he has no recollection of meeting Mr Gilmartin in his Department.
The only meeting he could recall, according to Government sources, took place over Flynn's pub in Drumcondra, Dublin, when Mr Gilmartin had briefed him on plans for a site on Bachelors Walk.