The creation of the international monitoring body, which will judge whether parties and paramilitary groupings are in breach of the Belfast Agreement, has been postponed until September, the Northern Ireland Office confirmed.
The body, which has been retitled the International Monitoring Commission, has been delayed because the US has yet to nominate a member. That nomination is expected next month.
The remaining three members drawn from the Republic, Northern Ireland and Britain have accepted positions, it is understood, although their names will not be released until the commission is formally established.
The commission which came out of the Hillsborough talks earlier this year was initially seen as something of a coup for Ulster Unionist leader Mr David Trimble. It ensured that in the event of devolution being restored, Sinn Féin could be penalised if the IRA breached its ceasefire.
Mr Jeffrey Donaldson and other anti-agreement Ulster Unionists supported by Lord Kilclooney (Mr John Taylor) claimed, however, that the commission would give Dublin an unacceptable role in Northern Ireland's internal affairs, which was contrary to the agreement.
This issue was part of the platform on which Mr Donaldson, the Rev Martin Smyth and Mr David Burnside effectively challenged Mr Trimble as UUP leader, and led to them resigning the Westminster whip but not resigning from the party.
Mr Trimble's efforts to expel the three MPs is now put on hold after the intervention of the courts and an attempt by former UUP minister Sir Reg Empey to find middle ground between the Yes and No camps of Ulster Unionism.
British government and pro-agreement Ulster Unionist sources are confident that the terms under which the commission is established will reassure unionists that the Irish Government is not interfering in Strand One matters that are the concern of the Assembly and Northern Secretary Mr Paul Murphy. Sources say the Irish Government is amenable to providing such assurance.
It will be for the commission to determine whether and how parties or paramilitaries have broken the demands of the agreement, it is understood. It will be for the Assembly and/or the Northern Secretary, however, to determine what sanctions, if any, should be imposed against defaulting parties, or parties linked to paramilitaries.
This issue could be crucial should the long-running dispute between Mr Trimble and Mr Donaldson, and the pro-and anti-agreement wings of the UUP, come to a head in the coming weeks. Mr Trimble is due to return from holidays on Monday week and sometime thereafter the UUP officer board must decide whether to proceed with disciplinary action against the three MPs, which could result in another leadership challenge, or find some compromise to avoid a possible implosion of the party.
How this battle within Ulster Unionism unfolds will also have an important bearing on whether the postponed Assembly elections can take place in the autumn.
