The two weapons inspectors appointed by London and Dublin to scrutinise IRA arms dumps will begin their work next week, the Northern Secretary, Mr Peter Mandelson, told MPs in the Commons yesterday.
The former general secretary of the African National Congress, Mr Cyril Ramaphosa, and the former Finnish president, Mr Martti Ahtisaari, will visit Belfast on Monday to discuss the methods of following through on what Mr Mandelson described as "a very significant development" by the IRA to put its arms beyond use.
In a statement to MPs outlining the recent developments in the peace talks, Mr Mandelson said he had shown himself to be anything other than an "easy touch" for the republican movement, but it was his judgment that the IRA's statement could be relied upon.
"For the first time there is a commitment to put weapons completely and verifiably beyond use in a context which is realistic rather than simply aspirational," he said. "A real prospect of actually achieving decommissioning - no longer just talking about it or setting conditions for it which make its realisation less likely."
He said he believed there were several "substantial" dumps containing weapons, explosives and detonators.
While he suspected the dumps would be in the Republic, he was not in a position to confirm this.
Mr Mandelson said the British government planned to restore the Assembly and Executive by May 22nd and both governments believed the full implementation of the Belfast Agreement could be achieved by June 2001.
And boosted by the IRA's statement, Mr Mandelson said he believed the conditions were in place for the Ulster Unionist Party leader, Mr David Trimble, to lead his party back into government "confident that their long-standing and proper concerns have been addressed".
The shadow Northern Ireland secretary, Mr Andrew Mackay, acknowledged the IRA's statement was "a significant development" and said loyalist paramilitaries now needed to move on decommissioning.
However, he said there needed to be guarantees that the IRA's arms and explosives would be permanently put beyond use.
He sought assurances about the process of inspecting IRA arms dumps and on what sanctions might be imposed if the inspectors reported that IRA arms had been moved or used.
He called on Mr Mandelson to confirm whether he would be prepared to suspend the Executive if the IRA failed to meet its commitment.
Mr Mandelson said the IRA's reference to a confidence-building measure was the "first stage" of making its arms secure. The next stage was for those arms to be completely and verifiably put beyond use.
Mr Trimble said that while the IRA's statement appeared to break new ground there were matters that should be examined.
It was essential that loyalist paramilitaries also moved on decommissioning their weapons.
Calling on Mr Mandelson to confirm that the process of putting IRA arms beyond use was in fact decommissioning, Mr Trimble said he wanted an assurance that confidence-building measures by the IRA were transitional "and not the end result itself".
Mr Mandelson assured the UUP leader that the process of putting arms beyond use was "a start, not an end".
"It is the beginning of a process. It is stage one. Further stages must follow."
However, he said he did not want to predict or speculate on what could be achieved by June 2001.
The UUP deputy leader, Mr John Taylor, also sought further assurances and asked for a guarantee that all the IRA's illegally held arms would be brought under control.
In response, Mr Mandelson declared that it was "our requirement and my expectation" that all IRA arms would be placed under control.
And in a strong message to Sinn Fein, he added: "If, in the unlikely but theoretically possible circumstance of the IRA ceasefire being broken . . . it would, of course, mean that it would be impossible for the political representatives of the republican movement to remain active participants in the democratic institutions that we are creating".
The former Conservative prime minister, Mr John Major, told MPs that recent developments justified the decision to suspend the Executive and its institutions. The process had been a "long trail" and London needed to be clear about whether the IRA's statement meant total decommissioning or partial and whether all the IRA's weapons would be made available in the arms dumps.