The cabinet will meet on Thursday to make a declaration deleting Articles 2 and 3 from the Constitution, so long as the power-sharing executive in Northern Ireland begins operating on that day as planned.
The British devolution order devolving powers to the Northern Ireland Assembly, the powersharing executive and the North-South bodies is expected to be made at midnight on Wednesday and the Cabinet will meet to enable the deletion of Articles 2 and 3 before 11 a.m. on Thursday, after a number of other formalities have taken place.
Once the change is made, it cannot be reversed, even if the executive collapses within months over the weapons decommissioning issue.
While the replacement of Articles 2 and 3 was approved in the May 1997 referendum on the Belfast Agreement, an unusual constitutional mechanism was approved at the same time, making this enactment conditional on the devolution of powers to the new political institutions envisaged by the agreement.
However, this leaves open the possibility that the institutions would collapse, while the amendments to the Constitution become permanent, reversible only by another referendum.
The existing Articles 2 and 3, which lay claim to Northern Ireland as part of the national territory, have been strongly opposed by unionists for many years. The replacement articles, if enacted, will state that Irish unity can come about only by consent, and makes clear that there is no territorial claim.
Under the agreement, the constitutional changes take effect and the institutions, including the executive, assume their powers "at the same time on the entry into force of the British-Irish Agreement". The agreement does not come into force until:
1. The enactment of British legislation stating that Northern Ireland remains part of the UK, but that its status can be changed with the consent of a majority in a poll in Northern Ireland;
2. The approval of the replacements of Articles 2 and 3 by referendum;
3. The enactment of the legislation needed to establish the institutions agreed in the Belfast Agreement;
4. The two governments have notified each other in writing that the above three events have taken place.
The first three conditions have been met, but the two governments deferred the formal exchange of notifications to this effect until an executive has been formed and the British devolution order transferring powers to the institutions set up by the agreement is made. These notifications will be signed in Dublin on Thursday morning by the Minister for Foreign Affairs, Mr Andrews, and the Northern Secretary, Mr Peter Mandelson, before the Cabinet meeting.