Mr Gerry Adams has issued his starkest warning yet that the continuing political vacuum in Northern Ireland could tempt unionist "rejectionists" and loyalist dissidents "to deliver a death blow" to the Belfast Agreement.
The Sinn Fein president emerged from more than an hour of talks with the British Prime Minister at 10 Downing Street insisting it was for Mr Blair "to recreate a context in which David Trimble can be reassured", thus enabling "forward movement" in the process and the immediate appointment of the power-sharing executive.
He urged Mr Blair and the Taoiseach, Mr Ahern, to proceed with their plan to reconvene last week's adjourned talks at Downing Street this Friday, warning that the upcoming European election contest meant that only "a relatively short window of opportunity" remained.
However, there was a growing impression in government and other circles last night that the forthcoming election may already have begun to impinge on the Ulster Unionist Party's approach to the ongoing negotiations, amid indications, too, of some tension between Mr Trimble and Mr Blair.
While Mr Adams said their meeting had been "fairly constructive" and described Mr Blair as "very focused" on the need to move quickly, Mr Trimble emerged from his earlier one-hour meeting with the Prime Minister offering a gloomy assessment of the prospects for an early breakthrough.
"I'm afraid that following on from the Sinn Fein conference at the weekend things do not seem to be particularly encouraging. It does look as if we didn't get the progress there could have been," Mr Trimble told reporters.
He continued: "The most optimistic thing we can do at the moment is keep pressing away and hope that in time - and I hope not too long a time - the republican movement will start to implement its part of the agreement."
The impression has been growing in recent days that Mr Trimble is coming under pressure from Downing Street to drop his demand for prior IRA decommissioning as the price of Sinn Fein's entry into government, in return for a statement about future republican intentions which would seek to offer some "certainty" about eventual decommissioning, coupled with guarantees of sanctions should the IRA fail to deliver.
However, while insisting that "a form of words" would not be enough in any event, authoritative Ulster Unionist sources last night maintained that no formulation offering the "certainty" of eventual IRA decommissioning had been given or shown to Mr Trimble.
The same sources told The Irish Times that they did not expect any significant development this side of the European election. However, the two governments, as well as Sinn Fein, are known to be concerned that a bad result for the UUP on June 10th could actually further reduce any room Mr Trimble may have for manoeuvre.