The latest intervention by Tanaiste Michael McDowell clearly signalled that the new PD leader was not going to pull out of government provided appropriate information on the stg 8,000 Manchester payment is given in the Dail on Tuesday. "I have an abhorrence of heads on plates and that also goes for delivering my own head on a plate, " McDowell said.

The comments from McDowell followed signals of growing annoyance in senior Fianna Fail ranks that he had issued an ultimatum about Ahern's future. "The Fianna Fail party is not going to change leader at the behest of McDowell. I appreciate he has his own constituency but he could have been more discreet with his responses, " one senior minister said yesterday.

Ahern and his advisers were continuing last night to work on a formula of words which would meet the Tanaiste's request for a "warts and all" account of the Manchester payment. With only 35 minutes allowed for Tuesday's debate, the opposition will have limited room to tease out the contradictions in Ahern's statements on the controversy.

Despite former junior minister Ned O'Keeffe's reservations about the PDs staying in government, Fianna Fail TDs contacted this weekend said the coalition should continue in office. There was also a consensus that, without further revelations, there was no prospect of a leadership heave. It was accepted, however, that the Taoiseach's reputation had been damaged. With several ministers defending Ahern in the media, Fianna Fail has been marshalling its members to send supportive messages into radio programmes.

The Taoiseach will face further embarrassment in coming months with an interim report from the Moriarty tribunal and Mahon tribunal inquiries into his close friend Des Richardson and former partner Celia Larkin . . . two confidants at the time of the 1993/94 payments.

He faces a more immediate difficulty, however, after it emerged yesterday that one of the 'loans' he received may have been drawn on an account held by NCB stockbrokers. Padraic O'Connor, NCB's managing director at the time, gave Ahern IR£5,000 in 1993.

Fine Gael said clarification was needed as to whether the money was treated as a gift, a loan or a political donation in the company's accounts. Labour's Eamon Gilmore said, "whatever about a personal friend not looking for repayment, how could a company like NCB provide a loan over 13 years without looking for repayment or charging interest?" Fianna Fail sources last night insisted Ahern's outstanding debt was with O'Connor and not NCB.

Last night, the opposition turned its criticism onto McDowell. "The PDs have clearly abdicated any credibility that they once might have had in addressing the issue of accountability in high office, " said Fine Gael's Fergus O'Dowd. Several PD figures predicted that the party would take a hit from the crisis. "No matter what we do, it will be the wrong decision, " one source said.