The Taoiseach and British Prime Minister have demanded that the issue of weapons decommissioning be "confronted and resolved once and for all" in the short time left for negotiation.
A further day of intensive talks will take place today with Government ministers and officials talking to Sinn Fein, the Ulster unionist parties and Mr Blair in a renewed effort to end the crisis over decommissioning.
At the end of a day of intense political contacts, which ended once again in a short breathing space for more talks, Mr Ahern and Mr Blair both called for "clarity" on the issue.
Basically, this is a demand that the Republican movement make it clear that it intends to decommission weapons before the May 2000 deadline set down in the Belfast Agreement. Such an unequivocal commitment has so far not been given, despite intensive efforts all week by the Taoiseach, his ministers and officials to extract such a commitment.
The Prime Minister's official spokesman said last night that Mr Ahern had given Mr Blair "his assessment that allows us to think there is a way forward".
The legislation allowing the Northern Secretary, Mr Peter Mandelson, to suspend the institutions of the Belfast Agreement is expected to receive royal assent next Thursday or Friday, giving at least another week before the institutions are suspended.
However, Mr Blair's official spokesman declined to respond to a question as to whether Mr Mandelson would act on this new power if "clarity" is not forthcoming by then. "Nobody wants to have to use that power", he told reporters last night. "But we have to make the contingencies that have to be made.".
Such reluctance to issue deadlines is mirrored by the Government. Government sources said last night that "after 19 months spent getting to where we are, we are not going to let it go very easily".
After his 105-minute meeting with Mr Blair in a hotel in the seaside town of St Austell in Cornwall last night, Mr Ahern said: "We have been in many tight corners in the last few years in this process and we are in another". He maintained progress had been made, but not enough, and more needed to be made.
"This issue must be dealt with in the manner set down" he went on. "We must have clarity, we must be honest to ourselves, to the people and the governments that what we sell is something everybody understands."
Mr Blair also said there had been "progress" but said "the Good Friday Agreement has to be implemented in all its aspects. That includes the issue of decommissioning. It has to be confronted and resolved in a clear way. This is the clarity that the situation demands."
"This is a critical moment, it is a serious moment, but we will try to make sure the process is successful."
Arriving in Cornwall, Mr Ahern said he was there "to report some progress". In response to a question he said he hoped the suspension of the institutions was not inevitable, saying "we have moved some way forward".
Mr Ahern and the Minister for Foreign Affairs, Mr Cowen, arrived to meet Mr Blair shortly after 9 p.m. after a day of intense talks again failed to produce the "clarity" he said he required from the IRA. He had two lengthy telephone conversations with Mr Blair during the day, as Mr Blair toured the southwest of England where rural and farm issues have been raised.
The time of the meeting and its venue kept changing as the day went on and crucial discussions seeking a clear IRA commitment to decommissioning continued.
The Prime Minister's spokesman last night echoed Mr Ahern's message that some progress had been made. "It is important that people do not over-exaggerate the extent of the crisis", he said. "There is a crisis, and we are working with the Irish and the others to try and get through it."