The Ulster Unionist leader, David Trimble, has said his party will walk away from any future power-sharing executive with Sinn Fein if the IRA fails to honour its pledges on decommissioning. Speaking to the BBC today, Mr Trimble said if the Ulster Unionist council votes in favour of returning the assembly executive, it would not be irreversible. Mr Trimble said he was considering putting to the Ulster Unionist Council next week a proposal to go back into government with Sinn Fein while reserving the right to review its participation.

Mr Trimble was accused tonight of shifting his position on a return to government with Sinn Fein because of resistance to the proposal from within his own party. Anti-Good Friday Agreement unionists claimed his position was weakening after he signalled that the party's continuing participation in a power-sharing would be conditional on the IRA delivering on its pledge to put arms verifiably beyond use. Rebel UUP MP William Thompson interpreted Mr Trimble's comments as an admission that he was unsure of his own position.

Sinn Fein's Martin McGuinness has described the vote facing the Ulster Unionist Council next Saturday as a defining moment in the peace process. When interviewed on RTÉ Radio, he said the choice facing the UUP was whether it was going to work with Sinn Fein, the British and Irish Governments, the SDLP and other parties to build a new future, or be responsible for dragging the North back to the bad old days of the past.

This afternoon Mr Trimble mounted a strong attack on the approach adopted by nationalists on issues such as police reform and the flying of the union flag. He said it is critically important to unionists that the name of the RUC will not disappear and will have an honoured place. In an interview on RTÉ Radio, Mr Trimble said that the mean spirited attitude adopted by nationalists on reform of the RUC is causing intense anger among the unionist community. The deputy leader of the SDLP, Seamus Mallon, has retorted that Mr Trimble should stop criticising nationalists and give his party strong leadership.

Mr Trimble today again insisted that the IRA's process of putting its arms beyond use is the same as the actual decommissioning of its weapons. Writing in the Belfast newspaper, the News Letter, Mr Trimble said the IRA's offer two weeks ago to make its arms unusable was equivalent to disarming. The UUP leader has a week to persuade rank and file party members to support a return to the power-sharing executive with Sinn Fein. A meeting of the 860-member Ulster Unionist Council that was scheduled for today has been postponed until next Saturday.