Questions and doubts persisted last night over the conflicting accounts of Gen John de Chastelain's report to the Taoiseach, Mr Ahern, and the British Prime Minister, Mr Tony Blair, about last week's IRA decommissioning act.
The Conservative party's Northern Ireland spokesman, Mr Quentin Davies, scored a parliamentary success when the Commons Speaker unusually allowed his request for a government statement on the issue.
This would be to clarify the contradictions between Mr Blair's statements in Hillsborough last Tuesday and to MPs on Wednesday, and the general's version of events to delegations from the DUP and the UK Unionist Party, apparently confirmed to Mr Davies by Gen de Chastelain by telephone yesterday.
However, the resulting Commons exchanges failed to advance the issue as Northern security minister Ms Jane Kennedy side-stepped a direct question from former Conservative minister Dr Brian Mawhinney as to whether the general had given Mr Blair and Mr Ahern information not included in his public statement.
Mr Davies told MPs: "Very unfortunately and regrettably for the people of Northern Ireland, the peace process and the credibility of the Prime Minister Gen de Chastelain has now made it quite clear that he never gave any additional information to the Prime Minister."
He said this left MPs with a simple choice. "We can either believe Gen de Chastelain or we can believe the Prime Minister."
However, Ms Kennedy stuck to the government line that the general had not breached his undertaking of confidentiality to the Provisional IRA. At the same time, she said Mr Blair and Mr Ahern had been able to learn more from their long discussion with the general about the nature of the decommissioning.
"In the lengthy discussions the Prime Minister and Taoiseach had with the commissioners they were left with a greater sense of the scale and nature of the act of decommissioning that had taken place than it was possible for him [the general] to disclose either in his statement or in the press conference," said Ms Kennedy.
Official sources last night played down suggestions that the British government's response had raised serious questions about Gen de Chastelain's credibility as chairman of the international decommissioning body.