The Taoiseach has declined to specify what political penalties might be imposed on Sinn Fein if the Provisional IRA is found to have authorised recent arms smuggling and the murder of Charles Bennett in Belfast.
A spokesman for the Government said Mr Ahern would not be responding to demands from the Fine Gael leader, Mr John Bruton, that he and the British Prime Minister, Mr Blair, identify what types of action by paramilitaries would disqualify their associated parties from participation in the Northern Ireland executive.
Sinn Fein continued to insist yesterday that the IRA ceasefire remained intact. And Mr Blair's spokesman confirmed that his chief of staff, Mr Jonathan Powell, will travel to the North shortly in another attempt to broker a deal between Portadown Orangemen and Garvaghy Road residents.
A man was arrested and arms seized during disturbances between loyalists and nationalists on Saturday in Portadown.
The security forces are continuing to investigate the murder of Mr Bennett and the attempt to import high-powered weapons by post from Florida last week.
However, a spokesman said the Taoiseach would not be "getting into the business of imposing any deadlines on the security forces for the production of reports on the involvement of paramilitary organisations in these events." Neither would he be responding to Mr Bruton's demand.
Mr Bruton argued yesterday that if Sinn Fein and the IRA were accepted as separate for the purpose of political accountability - as Mr Ahern seemed to suggest recently - then the Mitchell Principles and the principles of non-violence in the Belfast Agreement were "meaningless and unworkable." In that case, he continued, "the IRA could resume a full-scale bombing and assassination campaign and Sinn Fein ministers could still claim a right to hold their places in the executive on the basis that it had nothing to do with them."
Both Mr Ahern and Mr Blair, he said, should state: their joint understanding of the relationship between Sinn Fein and the IRA, and between the Progressive Unionist Party and the UVF; their joint understanding of the means for working out political accountability for violence, or threats of violence, by the IRA or the UVF; and their joint understanding of the types of paramilitary action which would disqualify their associated parties from executive participation.
If the two governments did not clear up these matters during the summer, the Fine Gael leader said, they would "be asking Senator Mitchell and Gen de Chastelain to navigate a fog without a compass," and that was not fair to them.
An official spokesman for Sinn Fein said yesterday: "The IRA ceasefire is intact as far as we are concerned." Earlier Assembly member Mr Alex Maskey had said that the cessation was "still holding."
The Progressive Unionist Party Assembly member, Mr David Ervine, however, expressed concern that in the light of current developments the IRA cessation was beginning to "unravel."
He observed, "We are beginning to see certain elements of the Provos looking like they are drifting away from their commitment to the Good Friday agreement. I think we are beginning to see things fraying at the edges."
An Ulster Unionist Party Assembly member, Mr Dermot Nesbitt, said it was difficult to reconcile the IRA claim that it had a definitive commitment to peace with the claims that it was involved in murder and gunrunning.