Sinn Féin chief negotiator Mr Martin McGuinness today urged the British Prime Minister Mr Tony Blair to ensure that Northern Ireland Assembly elections are held this autumn.
As Mr Blair met with the Taoiseach in London, Mr McGuinness said Mr Blair had to make a decision in the next two to three weeks.
Mr McGuinness said he believed elections could be held this year but agreed that the "window of opportunity" was narrow.
He said: "I think that Tony Blair has a big decision to make and he has to make that decision, in my view, over the next two or three weeks."
Speaking after a meeting of Sinn Féin leaders in Dublin, Mr McGuinness spoke of republicans' frustration at the slow progress in resolving the current impasse in the Northern Ireland peace process.
The institutions were suspended last October amid allegations of an IRA spy ring in Stormont.
Elections had been set for last May but were cancelled at the request of the British government. Since then, speculation has mounted that they could be held this autumn.
Mr McGuinness told reporters in Dublin: "I think it is absolutely vital that the British prime minister listens to what both Sinn Féin and the Taoiseach have been saying about how crucially important it is for us to have these Assembly elections this autumn.
"At today's meeting, there was an awful lot of anger and frustration expressed at the behaviour of the British government and the slow rate of progress."
He described the British government's position in relation to the cancellation of the elections as "absolutely untenable".
He said that most political parties in Ireland knew there was a need to see a new dynamic injected into the peace process, and said this was the only way to restore people's right to vote.
"I think the British Government cannot be unaware of the strength of opinion vis-a-vis the need to hold those elections as a matter of urgency," he said.
He added: "I think the British Government also needs to be very conscious that even if a date is set for the election, there is no guarantee whatsoever about what republicans can do because republicans are very angry. They are very frustrated. They are very resentful of the way the British government slapped down the Taoiseach and Sinn Fein and, indeed, others, on the issue of elections."
PA