Sinn Féin has claimed that the Independent Monitoring Commission (IMC), which is to be formally constituted today, will be used to exclude republicans and others from democratic politics.
The IMC will have a key role in determining whether the IRA and other paramilitaries have ceased activity mentioned in paragraph 13 of the Hillsborough Joint Declaration such as "punishment" attacks, exiling, weapons procurement, targeting and intelligence gathering.
The IMC was to have been a critical element of last autumn's aborted deal that was designed to restore devolution.
One of its functions was to assist in assuring unionists in particular that the IRA was ceasing activity, thus helping to persuade unionists to go back into government with Sinn Féin.
While that deal collapsed, the IMC will none the less adjudicate on whether the paramilitary bodies have halted activity, and if not will assess the extent of their actions.
It was also to have a role in determining whether the British government was meeting its commitments on demilitarisation.
Sinn Féin Assembly member Mr Conor Murphy said the IMC was outside the terms of the Belfast Agreement. "It is ironic that the only aspect of the Joint Declaration which the two governments have advanced upon is the IMC. They have repeatedly failed to implement their commitments on policing, demilitarisation, human rights and equality, all of which are within the terms of the agreement.
"The IMC reports will be based upon information supplied by securocrats. The IMC will be no more than a smokescreen to validate arbitrary acts of exclusion by the British Secretary of State," added Mr Murphy.
The members of the IMC are: Lord Alderdice, former speaker of the suspended Assembly; Mr Joe Brosnan, former secretary general of the Department of Justice in the South; Mr John Grieve, former deputy assistant commissioner in the London Metropolitan Police; and Mr Dick Kerr, a former CIA director general.
Its British and Northern Irish members, Mr Grieve and Lord Alderdice, would also rule on whether politicians and executive ministers were honouring their pledges of office should the Assembly and executive be restored. Mr Brosnan and Mr Kerr will have no function in Strand One matters solely relating to internal Northern Ireland affairs.