Former Northern Ireland talks chairman Senator George Mitchell is due to meet politicians in Northern Ireland during a crucial week for the peace process, it emerged today.
Senator Mitchell, who chaired the talks which led to the 1998 Belfast Agreement, will meet SDLP leader Mr Mark Durkan in Belfast tomorrow.
However, his visit will coincide with the start of a week of intense lobbying within the Ulster Unionist Party in the run up to next today's showdown between rival wings.
Ulster Unionist leader Mr David Trimble is facing a challenge from supporters of three rebel MPs - Mr Jeffrey Donaldson, Mr David Burnside and the Rev Martin Smyth - over attempts to discipline them for resigning the party whip.
The MPs took their protest action in June in a row over party policy.
They wanted Ulster Unionists to completely reject proposals drawn up by the British and Irish governments which would pave the way for a monitoring body to be set up to determine if action needed to be taken against parties and paramilitary groups who breach the Belfast agreement.
Nationalists are also growing increasingly concerned at reports that British Prime Minister Mr Tony Blair will throw Mr Trimble a lifeline ahead of next Saturday's meeting of the 900 member Ulster Unionist Council, by announcing that the Irish government would not have any role on the body in assessing breaches of the paramilitary ceasefires.
As they prepared for tomorrow's meeting with Senator Mitchell, an SDLP source said Unionist opposition to a role for Dublin was "bizarre".
"Does the Ulster Unionist Party think the Dublin government has no role to play in working to end paramilitary activity throughout the island of Ireland?" he asked.
"Do they think paramilitary activity does not exist in the south?" Under the British and Irish government proposals, four nominees would be appointed to the monitoring commission.
Two of them would be British, one would be nominated by the Irish government and a fourth would come from the United States.
Ulster Unionists are hopeful that the British government will separate the functions of the Irish and US nominees from any matters affecting the internal affairs of Northern Ireland.
Unionists have argued that it would be wrong for an Irish official to have a say on whether action should be taken against a party in breach of the agreement because that is purely a matter for the British government and the parties in Northern Ireland.
PA