Tony Blair has insisted a deal can still be reached to allow the re-establishment of the Northern Ireland power-sharing executive.

The prime minister warned that further talks were needed before an election date for the suspended Stormont assembly can be announced.

He told MPs there was no way the province could return to the troubles of the past.

"I believe that the agreement in Northern Ireland has delivered tremendous benefits for people of Northern Ireland over the past few years," Blair said.

"I don't think anybody, if they returned to Northern Ireland now after an absence say of seven, eight or 10 years could fail to see the progress that is being made."

But the prime minister also warned that there was only one possible deal for the parties to work on.

"The agreement we've got is the only agreement that's on offer," Blair said.

He was speaking as the statutory deadline for the announcement of the stalled elections passed.

The lack of an official announcement brought concern from MPs involved with Northern Ireland affairs, who demanded to know why ministers had failed to recognise their own deadline.

Shadow Northern Ireland secretary Quentin Davies raised the issue as a point of order in the Commons and was joined by UUP leader David Trimble, Peter Robinson of the DUP and Lembit Opik of the Liberal Democrats.

"The silence itself is causing instability," warned Opik.

But Downing Street had earlier given an upbeat assessment of the situation.

"There is a positive atmosphere and there are real discussions going on," said the prime minister's official spokesman.

Whilst Number 10 advised all parties against concluding that imminent elections were inevitable it remained confident about future progress.

British sources are privately hopeful that the IRA is on the verge of a major act of decommissioning which could bring unionists and republicans into agreement over the timing of elections to the devolved assembly.

Days of intensive negotiations have failed to produce the breakthrough that Tony Blair and Irish prime minister Bertie Ahern had hoped for.

Exactly a year ago today the Northern Ireland assembly was suspended following allegations of a spy ring operated by the IRA.

Many predict that November 27 is now the most likely date given that during the previous week schools usually used as polling stations are holding exams.