Taoiseach Bertie Ahern has insisted that money he received in the early 1990s was raised by friends, despite stockbroker Padraic O'Connor's evidence that he did not contribute to a personal fund.
Speaking in Dublin, Mr Ahern said: "I said in the past that those who gave me money . . . it was raised by friends and I still say that that is exactly correct.
"The second thing is that I thought that Padraic O'Connor was a very good friend of mine. If he has changed his mind, I can't do anything about that," the Taoiseach said.
In his October 2006 interview on RTÉ television, Mr Ahern claimed that his solicitor, Gerry Brennan, had gone to a number of personal friends of his in the run-up to Christmas 1993.
He also then said that he had repeatedly tried to repay the money but "they refused to take it", though some of them had said that they then lodged it with his constituency organisation if he gave it back.
Fine Gael leader Enda Kenny was repeatedly critical of Mr Ahern's tribunal evidence during public appearances in Cork city yesterday, saying that Mr O'Connor's testimony had seriously undermined Mr Ahern.
"The explanations given by him are crumbling and crumbling fast and senior Ministers in Fianna Fáil who have given blind allegiance on this are going to have to answer for this in due course," he said.
Fine Gael Senator Eugene O'Regan said what is now emerging is that there never were dig-outs or whip-rounds to collect money from personal friends of Bertie Ahern.
"This was the main selling-point of the Taoiseach's story in his RTÉ interview last year, but this claim has been described as 'untrue' by one of the supposed 'dig-out' contributors, Padraic O'Connor.
"The dig-outs were the linchpin of the Taoiseach's story and the one that evoked most public sympathy after he was afforded airtime in an interview on the RTÉ six o'clock news with Brian Dobson.
"The fact that the tribunal is looking for full discovery of the accounts of Des Richardson - the Fianna Fáil fundraiser - suggests that the tribunal is not at all satisfied with the Taoiseach's evidence to date.
"Padraic O'Connor's evidence this week totally contradicts and undermines the Taoiseach's evidence on the alleged dig-outs," Mr O'Regan said.
"He stated that he was not a personal friend of the Taoiseach, that the NCB payment was not a personal loan, and that there was no discussion with the Taoiseach about any payment being made on the basis of a loan.
"We are still awaiting a plausible explanation of the €300,000 in lodgments to the Taoiseach's accounts in 1994 and 1995," said the Dún Laoghaire-based Senator.