The Taoiseach, Mr Ahern, and the British Prime Minister, Mr Blair, are expected to hold urgent talks on Northern Ireland this weekend on the margins of an informal EU summit in Austria.
And while officials on both sides insist there are no such plans, there is continuing speculation that the two leaders could be forced to take their shuttle diplomacy to the North as the October 31st deadline for the next stage in the Belfast Agreement draws near with no sign of a compromise between the Ulster Unionists and Sinn Fein on decommissioning of paramilitary weapons.
There is obvious reluctance in both capitals about launching a high-profile prime ministerial initiative, in what would be seen as a re-run of the final stage of the multi-party negotiations which concluded with the agreement on Good Friday.
But pressure was mounting on the Taoiseach and the Prime Minister last night after Mr David Trimble and Mr Martin McGuinness emerged from separate meetings with Mr Blair at 10 Downing Street each insisting that the other must make the next move to break the impasse. A spokesman for Mr Ahern said there would be telephone contact between the two prime ministers in the run-up to the meeting in Austria.
Number 10 had played down hopes for an early breakthrough in advance of yesterday's meetings, saying it was important for Mr Blair to form an up-to-date assessment of the situation. And afterwards a spokesman claimed some advance in that "each side recognises the difficulty of the other". He also said the October 31st deadline for the next steps under the agreement was "an important catalyst" and expressed confidence that it could be met.
That renewed focus on the October 31st deadline was welcomed by Irish Government sources. At the same time it seems clear there is no definitive agreement between London and Dublin as to whether progress on areas for North-South co-operation and the implementation bodies requires the prior creation of the shadow executive and the North-South ministerial council.
After more than 100 minutes of one-to-one talks with the Prime Minister, Mr McGuinness trenchantly insisted that it did, telling Mr Trimble it was time to "face down" internal party opponents who were opposed to the agreement "lock, stock and barrel".
Drawing a distinction between unnamed senior political figures and "the unionist grassroots", Mr McGuinness quoted Mr Gerry Adams and declared: "These are people who don't want a Fenian in the place."
He continued: "I believe David Trimble's in a very strong position, particularly in the aftermath of the Omagh bomb, and in the aftermath of the award of the Nobel Peace Prize to himself and John Hume. And I think there is an expectation now that those people within unionism who are opposed to the Good Friday Agreement must be told that the game is up and that we are pressing on decisively to implement the full agreement."
Mr McGuinness said the decommissioning issue was "always a matter for General de Chastelain and his International Body, and I think the path to decommissioning should be left to him".
But Mr Trimble emerged from his one-hour meeting with Mr Blair insisting the republican movement must begin decommissioning and predicting, again, that it would. "I rather expect the republican movement will continue to say `no' until five minutes before the end," he said.
But without movement on decommissioning, Mr Trimble told reporters: "Our judgment is there would not be sufficient confidence for an executive to come into being without evidence of people being committed to exclusively peaceful and democratic means, and so far Martin McGuinness has not satisfied that requirement. We will continue to make progress as best we can, with or without Mr McGuinness."
In the wake of yesterday's London meetings, the Taoiseach last night said the "will and determination is there to realise the full vision of the agreement".