Talks to restore power sharing in Northern Ireland have reached a "high wire stage", sources from both government claimed tonight.
As attention switched to tomorrow's Ulster Unionist Party conference in Armagh, sources in London and Dublin were encouraged by the intense negotiations between the UUP and Sinn Féin.
But a talks source cautioned: "We are not near a deal yet.
"The negotiations right now are very sensitive. We have reached a high wire stage where one wrong move could mean a deal falls down.
"Certainly everyone appears to be moving in the right direction. Tomorrow's speech by David Trimble at his party conference could be crucial."
Earlier today the Taoiseach, Mr Ahern suggested time was running out for a deal enabling Assembly elections to take place next month in a positive climate.
At the summit of European Union the Taoiseach said: "If we don't have elections, I think we are into an enormous period of uncertainty.
"It's very hard to tell people that you are heading for a sixth year without an election on what was a five-year mandate - and that you are still not having elections. We need a big jump."
As Sinn Féin's officer team reviewed the peace process at a meeting in west Belfast, the party's chief negotiator Mr Martin McGuinness acknowledged there was "a degree of nervousness" in all communities as they waited for an outcome in the negotiations.
With most parties in Northern Ireland anticipating a pre-Christmas poll, the Mid Ulster MP again warned if no election took place this year it could spell "the end of the Good Friday Agreement".
"That would mean the rejectionist unionists would have had their way.
"We in Sinn Fein are quite settled in our view that there is going to be an election shortly and that means this year."
A British Government source tonight believed the deadline for a breakthrough would come early next week.
An Irish government source said: "If we get the substance right and agreement, then we can expect the choreography to kick in within a very tight timeframe."
Other talks sources placed great emphasis on Mr Trimble`s conference speech which was expected to address what republicans need to do to advance the peace process and his internal row with three rebel Ulster Unionist MPs.
A source said: "Tomorrow's speech is pretty important when you consider that two weeks ago the talks were slightly derailed by the negative tone the UUP's executive adopted towards the joint declaration [the British and Irish governments' plan for implementing the Belfast Agreement].
"That threw a spanner in the works because Sinn Fein started to question the Ulster Unionists' pro-Agreement credentials.
"If David sends out strong signals tomorrow that the Agreement is the only game in town and he is committed to inclusive stable government that will undoubtedly help the mood music."Devolution was suspended in Northern Ireland last year amid allegations of IRA spying at Stormont.
Although the Provisionals have refused to sign up to an historic declaration that they are ending all paramilitary activity, talks participants are hopeful of a significant move on weapons.