Sinn Fein and the Ulster Unionists were locked in a bitter war of words in Downing Street last night, underlining the very real threat now hanging over the Belfast Agreement.
In Belfast, Senator George Mitchell insisted that the agreement could be salvaged, while in Dublin Gen John de Chastelain maintained that decommissioning could be completed by the May 2000 target date.
But in London Mr David Trimble denounced Sinn Fein "lies" and claimed himself vindicated by Wednesday's "menacing" IRA statement, while Mr Gerry Adams said that an agreement which remained "merely aspirational" while being "torn to shreds by rejectionist unionism" was "not worth an awful lot".
After his one-hour meeting with Mr Trimble's UUP delegation - and talks lasting twice as long with the Sinn Fein leadership - a Downing Street spokesman said that the Prime Minister, Mr Blair, considered the latest exchanges "useful and constructive". While difficulties remained, the Prime Minister continued to believe that the parties did want to make progress.
But evidence to support such optimism was thin on the ground as the fall-out continued from last Thursday's failure to establish the power-sharing executive. Mr Trimble openly questioned the commitment of Mr Adams and Mr Martin McGuinness to the process.
Senior Sinn Fein sources, meanwhile, briefed journalists on the apparent "consensus view" now within the republican movement that "the UUP does not want the agreement to work, hopes to blame Sinn Fein for its failure, and to put something else in its place".
Responding to the IRA statement, Mr Trimble said: "One of the things we all have to consider is: where is the seismic shift in republican attitudes we were told had occurred?" The process had failed last week because there had not been assurance either that the paramilitaries would meet their obligation to disarm or "from the other democratic parties that they would support us if they [the paramilitaries] did not".
Clearly signalling no shift in his position, Mr Trimble said the republican movement and the other parties would "have to reflect on that over the next six weeks" and "realise that this process is not going to work unless adequate assurances are given to all the parties, and that, of course, includes us".
But Mr Martin McGuinness said: "Unless the unionists and the British government play their part within this process, in my opinion there is no prospect whatsoever of the armed groups decommissioning . . . before next May . . . The unionists and the British government have to recognise there is no singular responsibility on Sinn Fein to deal with the issue of decommissioning."
Mr McGuinness said that he had told Mr Trimble and Mr Blair in recent weeks that "ultimately they will have more influence over the IRA than Gerry Adams and I ever will". He continued: "That's a very clear message. The responsibility to deal with this issue is a collective responsibility - it includes David Trimble, it includes Tony Blair, it also includes Sinn Fein.
"We are prepared to play our part. But the task we have been set, in the context of no political change . . . is, in my opinion, an impossible one. So it's everybody's shoulder to the wheel, not just Sinn Fein's."
While Sinn Fein had acknowledged Mr Blair's contribution, Mr Adams said, the reality was that "unionists have been able to ride roughshod over all of that, and proactively and actively prevent the implementation of the agreement, which the British government is party to".
Sinn Fein, he said, would not interpret "that [IRA] statement from an organisation which we don't have any authority, control or responsibility for".
Listing the scale of loyalist attacks against nationalists, the murder of Ms Rosemary Nelson, the failure to secure an independent inquiry into the murder of Mr Pat Finucane and the further delay in the Bloody Sunday inquiry, Mr Adams said: "We are in real trouble, not because of IRA statements or statements from other individuals, but because the expectation raised in the Good Friday agreement . . . has been undermined by those who don't want change."