The Ulster Unionist Party is expected to rule out direct negotiations with Sinn Fein when its executive meets today to discuss strategy for the Stormont talks.
Unionist attitudes have hardened since this week's IRA statement that it had problems with the Mitchell Principles. It is understood that the UUP will call on the British government and the talks chairman, Senator George Mitchell, to first clarify Sinn Fein's position in negotiations.
Ulster Unionists will rule out direct dialogue with republicans until it is established whether Sinn Fein represents the IRA at talks and whether it is in breach of the Mitchell Principles.
As the Minister for Foreign Affairs, Mr Burke, warned the unionist parties that they ran the risk of being by-passed by the people if they failed to engage in negotiations, senior UUP sources said last night that while the final decision was Mr Trimble's the mood would be against negotiating with republicans.
The British Prime Minister, Mr Tony Blair, also appealed to the UUP to enter all-party talks, saying it was better for unionists to articulate their case case inside, rather than outside, negotiations.
But a UUP figure said: "The IRA has effectively pulled the carpet from under the talks process. It has totally wrecked the chances of any positive response from Ulster Unionists at the moment. We have little room for manoeuvre. It's just a case of kick for touch. The real decision on negotiations will be postponed. We cannot be rushed into anything now."
The 111-member committee will meet at party headquarters in Glengall Street. The UUP's nine MPs will be present. The debate should last two hours and Mr Trimble will hold a press conference later.
The UUP source said Mr Trimble would be eager not to appear negative and there was no question of the UUP withdrawing from talks. But the party would refuse to take part in direct discussions with republicans next week, he said. "It is up to the government and Senator Mitchell to establish if Sinn Fein . . . will be speaking for the IRA at talks just like it has been established that the loyalist parties speak on behalf of the loyalist paramilitaries."
???ein signed the Mitchell principles and 48 hours later the IRA rejected them. The onus is on George Mitchell and the government to now clarify the situation and rebuild our trust."
Mr Trimble yesterday called on the government for assurances from Sinn Fein that the IRA would decommission weapons during talks. Otherwise, sanctions must be imposed on republicans, he said.
Mr Burke, addressing the annual conference of the BritishIrish Association, rejected the notion that a political agreement which was good for nationalists must be bad for unionists. He asked: "Would it not represent a failure of nerve if those who complain about the attention given to the concerns of Sinn Fein were to fail to challenge Sinn Fein's position in direct debate?"
Mr Blair, speaking on Ulster Television last night, reiterated that there would be no change in the constitutional status of Northern Ireland without the consent of a majority of the population. He said Sinn Fein and the IRA were "inextricably linked" and warned that if Sinn Fein did not adhere to the Mitchell Principles, it would be ejected from talks.
But writing in today's Irish Times, Mr Gerry Adams says that Sinn Fein's peace strategy goes much further than the Mitchell Principles. "As always our party will honour our commitment and we will try to ensure that others do likewise," he says.
"The most important thing is that the IRA has called, and adhered to, a complete cessation - a fact acknowledged by the British government's military advisers." He describes the "political storm" created by the IRA's comments as "astonishing and offensive when one considers the lack of comment on loyalist, unionist and British breaches of the Mitchell Principles".