The first working sessions of the 1998 Good Friday Agreement review are being chaired by British Direct Ruler Paul Murphy at Stormont.
At last week's round-table opening session, the British and Irish Governments and parties elected in last November's assembly election read statements outlining their positions.
The political institutions in the North were suspended in October 2002 amid allegations of an ``IRA spy ring'' at the Stormont headquarters of the devolved local government.
However, the principal charges brought against those involved, including the head of Sinn Féin's office at Stormont, have now been dropped.
When the 1998 Agreement was signed it contained a commitment that a conference should be held four years later to review and report on its operation.
But Stormont has been suspended four times and replaced with direct rule for the past 14 months.
The parties differ about what form the review - expected to run until Easter - should take, with the DUP saying it will not negotiate with Sinn Féin. Sinn Féin and the SDLP have ruled out any renegotiation of the Good Friday Agreement.
DUP deputy leader Peter Robinson said his party would hold meetings to let grassroots unionist groups know what happened.
``I think that was one of the major failings of the Ulster Unionists - people didn't understand what was happening,'' he said.
On Friday, the DUP said in its proposals for restoring devolution that the assembly could get up and running in the short term, before the existing dispute over IRA arms and activity were resolved.
However, Ian Paisley's party repeated its insistence that there could be no place for republicans in a power-sharing executive until the IRA ceased activity.
Sinn Féin Mid Ulster MP Martin McGuinness has said that the British and Irish Governments must defend the Good Friday Agreement.
Speaking after Sinn Féin met with British and Irish officials, Mr McGuinness said the two governments had said that the Agreement is not up for renegotiation.
``They need to demonstrate this commitment by lifting suspension.
``Sinn Féin impressed on the British and Irish governments the need for this review to be carried out in the proper context. Lifting suspension will concentrate minds on how the review can lead to the effective implementation of the Agreement.''
His party has repeatedly accused the British government of undermining political stability and confidence by its lack of commitment to the Agreement.
Mr McGuinness said that the All-Ireland elements of the Agreement were ``interlocking and interdependent'' with the Assembly and Executive. ``There won't be an Assembly unless the All Ireland agenda is fully functioning.''
In response to recent proposals by Ian Paisley's DUP, Mr McGuinness added: ``The DUP in their document explicitly demand a new Agreement. There will be no renegotiation of the Agreement. These proposals are clearly about a return to unionist majority rule. This is not acceptable. Sinn Féin will not allow a return to the misrule and abuse of power that was the hallmark of unionist rule in the past.''
The SDLP has said the DUP's model sounded like the assembly of 1982, which had not worked.
Party leader Mark Durkan, said his party rejected the idea of a council-style Assembly before the Good Friday Agreement was concluded, and he rejected it again.
``The SDLP is clear. We have no interest in internal solutions for the North. We have no interest in majority rule by the back door,'' he said.
``Our interest is in getting the Good Friday agreement up and running again. We don't just want to implement the Good Friday agreement, we want to develop it. We want to bring it back bigger and better than before.''
Ulster Unionist leader David Trimble said the DUP proposals would allow Stormont to come back without the underlying problem being resolved - continued paramilitarism.
He said: ``I don't think that those who voted for the DUP voted for that''.