The British and Irish governments will this week attempt to steady political nerves after Mr David Trimble embarked on phased sanctions against Sinn Fein that threaten the stability of the Belfast Agreement.
Mr Trimble survived the Ulster Unionist Council meeting on Saturday - but only after promising he would prevent Sinn Fein Ministers from attending North-South Ministerial Council meetings until the IRA fully engages with the International Commission on Decommissioning.
The first casualty of Mr Trimble's decision to institute penalties against Sinn Fein will be a health and food safety North-South meeting in Enniskillen on Friday, which Sinn Fein Minister of Health, Ms Bairbre de Brun, and the Minister for Health, Mr Martin, were to attend.
The Irish Government has conceded that under the Northern Ireland Act 1998 Mr Trimble has the power to determine whether such meetings can take place, and Mr Martin will not now be going to Enniskillen.
Under the Act Mr Trimble and the Deputy First Minister, Mr Seamus Mallon, must agree who should attend North-South meetings. If they can't agree, these meetings must be cancelled, which should mean that Mr Trimble could block Ms de Brun and Mr Martin McGuinness from participating in the North-South element of the agreement.
The Sinn Fein president, Mr Gerry Adams, claimed the Trimble motion was in breach of the agreement. Mr Mallon indicated that the legality of Mr Trimble's proposals may be tested.
The Taoiseach, Mr Ahern, and the British Prime Minister, Mr Blair, are to have a telephone discussion today on the latest turmoil in the political process. The Minister of Foreign Affairs, Mr Cowen, and the Northern Secretary, Mr Peter Mandelson, are also due to meet later this week.
Dublin and London have urged Northern politicians, particularly those in Sinn Fein and the SDLP, to approach this situation carefully. They drew some consolation from the fact that Mr Trimble saw off the challenge from Mr Jeffrey Donaldson and the No wing of Ulster Unionism, which wanted to set a deadline of November for IRA decommissioning.
The set of sanctions adopted by the council also demands that the decommissioning body adopt a pro-active role, a moratorium on police reform, and a formal review of the agreement if there is no progress on weapons.
Mr Donaldson, while disappointed not to succeed with his motion, argued that the No wing of unionism forced Mr Trimble to harden his position on arms.
Sinn Fein met yesterday in Castlebellingham, Co Louth, to consider the implications of Mr Trimble's motion. Mr Adams said later: "The two governments should make it patently clear that there is no one who is going to chew away at or tear off or break up or have an a la carte attitude to the implementation of this agreement. What I am saying on behalf of Sinn Fein is that we are not going to take this lying down."
