The former deputy first minister Seamus Mallon has criticised the Northern Ireland Secretary for putting Ulster Unionist interests first by suspending the assembly.

Mr Mallon has also called on the British and Irish governments to confirm that more information was available on the IRA's intentions to start decommissioning its arms, than had been made public.

His comments came after the Peter Mandelson suspended Northern Ireland's political institutions on Friday despite news that the decommissioning body was due to release a second report on progress towards IRA decommissioning.

Mr Mandelson is due to address the British-Irish Parliamentary Body made up of 50 British and Irish MPs about the current situation in the peace process, in London on Monday.

Speaking on the BBC's Seven Days programme on Sunday Mr Mallon said the Northern Ireland Secretary had made a "faulty decision" bowing to the pressure of David Trimble's promise to his party that he would resign from the assembly if there was no IRA decommissioning by 31 January.

He said: "By making this decision at this time Mr Mandelson made the needs of the UUP the greater priority where in effect the greater need that (he) must serve is the greater interest of all the people and the agreement."

Mr Mallon said that despite Ulster Unionist leader David Trimble's assertion that in the Mitchell review it was agreed that IRA decommissioning must start by 31 January, "the real outcome of the Mitchell review was that we all agreed that the matter would be left to the assessment and judgement of general de Chastelain".

The deputy leader of the nationalist Social Democratic and Labour Party said he believed the British and Irish governments knew that there had been more developments in relation to IRA disarmament than general de Chastelain's commission had reported on Friday.

Mr Mallon said: "The general refers in paragraph seven of his report to the fact that he has other information.

"Now I know that to be the case and that that further information in terms of possibility two other statements would have had remarkable significance in terms of what Mr Mandelson might have considered doing.

"Even at this late hour what I am suggesting and asking is that the two governments confirm that they are aware of other factors that influenced General de Chastelain in terms of his second report."

Mr Mallon added that with all the facts he believed "we will be to answer the questions, will (the IRA) decommission and if they will, when?"

'Disarming prospect weakened'

Mr Mallon said that the fact that the political institutions had been suspended had "fundamentally weakened" the opportunity to obtain paramilitary decommissioning.

But he said he believed all the politicians are mature enough to realise that the peace process "is not about winning the last argument it is about getting on to the next challenge" and make progress when it goes into review next week.

But he called on both Sinn Fein and the Ulster Unionist Party leadership to stop letting "unelected people with no mandate" in the IRA and in the Ulster Unionist Council dictate what happened in the peace process and to "lead from the front".

Mr Mallon's comments follow repeated demands from David Trimble made on the BBC's Breakfast with Frost programme that republicans should "make their minds up" whether they wanted to be involved in politics or terrorism.

Mr Trimble added that a re-established power-sharing Stormont executive could only include Sinn Fein if it "clearly and unequivocally demonstrated its commitment to peace and democracy".

But Sinn Fein's Bairbre de Brun told Sky News that the assembly suspension was a "disaster" and that the arms issue was a matter solely for the de Chastelain Commission to resolve.

Meanwhile the smaller parties have also been expressing concern.

Monica McWilliams of the Women's Coalition said she was "appalled" by the way the suspension of the Assembly had been handled and called on the pro-agreement political parties to set up a working group to steward the implementation of the Good Friday Agreement.

She said: "We don't want to see anybody walking, although people are very dismayed and hurt and angry we need to get back round that table."

David Ervine of the Progressive Unionist Party which is linked to the paramilitary Ulster Volunteer Force said his party may not join in any review.

He said: "In real terms it was always going to be easy to get into suspension. My question is how the hell do we get out of it?

"We are in a serious, serious crisis and I don't think people realise how deep a crisis it is."