The Ulster Unionist leader has said the decommissioning element of the Mitchell deal will not be allowed play a secondary role to devolution. Interviewed tonight on a BBC Northern Ireland programme, David Trimble said that he expected the decommissioning body, headed by General John de Chastelain, would closely monitor progress in the handing over of paramilitary weapons. He also acknowledged concerns about the consequences of the IRA defaulting on the deal and said that the attitude of the SDLP would be crucial in deciding whether Sinn Féin should be punished for IRA inaction. Mr Trimble refused to be drawn on whether he would resign if he loses Saturday's vital vote of the Ulster Unionist Council, saying that he was not contemplating failure.

Anti-Agreement forces, including the Democratic Unionists, have stepped up their campaign. DUP leader, Ian Paisley, said that he thought it was probably too close to call, but he did not believe Mr Trimble was heading for the kind of victory on Saturday he had before. Earlier, the Northern Secretary appealed to Ulster Unionists to support their party leader in Saturday's crucial council vote on the Mitchell plan. Peter Mandelson told them that, if they grasped the opportunity, they would find out whether Republicans were for real, but warned that, if they rejected it, they might never know.

Mr Mandelson used his speech to a group of secondary students at Victoria College in South Belfast to appeal directly to Ulster Unionists. He called on them to put aside the fear of failure and to present the face of a progressive, tolerant, confident Unionism, which was comfortable in co-existing with those who held a democratic Nationalist aspiration. The Northern Secretary said that, like George Mitchell, he believed decommissioning would happen as Gerry Adams and Martin McGuinness of Sinn Féin were forward-looking politicians and realists, who would use their influence to make it occur.

Mr Mandelson said he hoped passionately that the Ulster Unionist Council would decide to break the dead lock and accept the Mitchell Review proposals when they meet on Saturday. Mr Mandelson's comments were criticised by the DUP leader Ian Paisley who said that he treated them with contempt. David Trimble claimed earlier today that a dirty tricks campaign is being waged in an attempt to have the Mitchell proposals rejected at Saturday's meeting of his party's ruling council. Some of those entitled to vote at Saturday's meeting have received bogus letters purporting to come from Sinn Féin urging them to support the Mitchell plan. The letters, which are allegedly signed by Gerry Adams, tell delegates that they know that Britain wants out of the North and recommends a “yes” vote, so that both communities can move forward together.

David Trimble blamed Unionist hard-liners from outside his own party, while Sir Reg Empey said that the Council would not be deflected by physical intimidation or by what he called cheap dirty tricks. Last night, his fellow negotiator, Dermot Nesbitt, claimed that he had been assaulted after a meeting in Newcastle County Down. On Monday, David Trimble and Peter Mandelson were abused and heckled near Portadown. Mr Nesbitt was struck by one of the crowd of about 25 anti-Agreement demonstrators who had gathered outside. The tyres of his car were also let down. The RUC escorted Mr Nesbitt away from the area. Afterwards, he said that there was no call for such intimidation. However, a DUP Assembly member, who was among the crowd, said that police told him the protest had been extremely well behaved. Mr Trimble also denied a suggestion in the Financial Times that he would resign as first minister by the end of January if there was no decommissioning. He said that it was inaccurate and that deadlines were not helpful in the current context. He said that he would be looking carefully at the text of the speech by Peter Mandelson.

The Alliance party leader has said that the full implementation of the Good Friday agreement is the one and only choice for the people of Northern Ireland. Sean Neeson said that he was greatly disturbed that leading anti-Agreement elements were being motivated by what he said was bitter sectarianism. He said that his view was reinforced by the production of a recent video by them highlighting the plight of victims, as well as the public utterances of people such as the West Tyrone MP, Willie Thompson, who said that he would not share power even with the SDLP.