The IRA has blamed David Trimble for the recent breakdown in the Northern Ireland peace accord.

In a statement issued on Wednesday, the organisation ruled out further decommissioning before moves by the Ulster Unionist Party.

The moves failed to materialise last week, after Trimble called for clarification of the latest weapons to be given up.

"The political process these initiatives were designed to facilitate has been halted without a credible explanation from those who stopped it," said the IRA statement.

"The leadership of the IRA honoured our commitments. Others have not fulfilled theirs. This is totally unacceptable.

"When we give our word we keep it. We expect others to do the same. Until they do so there can be little prospect of progress on the issues they profess concern about."

Earlier in the day the prime minister insisted he was given a more detailed assessment of the IRA's decommissioning than that released by the weapons chief last week.

Tony Blair told the Commons that General de Chastelain, the head of the international decommissioning body, told him "certain information" about what the IRA had destroyed.

The prime minister reaffirmed his belief that unionists would accept the IRA's gesture if they possessed the same information.

Blair also repeated his support for the Good Friday agreement, urging rebels within the Ulster Unionists to do the same.

"There is no other agreement on offer than the one that we negotiated with painstaking difficulty over a number of days," he said.

"I hope very much that as a result of what happens over the next few weeks that we are able then to take that agreement forward and implement it in full...it's important we carry on working to bring about a peace that is lasting and durable."

Earlier, Liberal Democrat Northern Ireland spokesman Lembit Opik asked the government to end the ambiguity.

"Did the prime minister have insider knowledge? If he did, where did he get it?" asked Opik.

Despite the row, the Northern Ireland secretary claimed significant developments had been made in recent weeks.

Paul Murphy made a wider appeal to the people of Northern Ireland to look beyond the November 26 polling day, rather than focus on immediate problems.

"The issue in front of the people of Northern Ireland are the elections and the future of Northern Ireland after the election," he said.

"The people of Northern Ireland must draw hope from the fact that the parties have engaged on the issues of the day."

The government wanted to create a culture where progress could be achieved, added Murphy.

"We sincerely hope that after the elections conditions will be created that permit a working executive to be formed and all aspects of the joint declaration to be taken forward," he said

The former leader of the nationalist SDLP, John Hume, argued that "the people of Ireland as a whole, North and South have overwhelmingly declared how they wish to live together".

"It is the duty of all true democrats to implement the will of the people, and to implement the Good Friday agreement," he said.

And Seamus Mallon, the party's former deputy first minister in the assembly, said it was time to take the peace process away from "the men in balaclavas and... bowler hats".

Unionist chief David Trimble told MPs that republicans had to show they were committed to ending all violence in the province.

"If the sequence which it was necessary for me to put on hold last Tuesday is... to be resumed it would be essential that through the next few weeks during the election campaign that republicans should abide very clearly by the commitments to peaceful means that they made at that stage," he said.

However, one Ulster Unionist Party rebel, Rev Martin Smyth, questioned the extent and rate of decommissioning by the IRA.