The leader of the Ulster Unionist Party, Mr David Trimble, was last night reconsidering whether to proceed with a planned visit to the United States which would result in his absence from the Northern Ireland talks.
There was considerable surprise yesterday when it was learnt that Mr Trimble intended to fulfil lecture engagements in the US at this crucial stage of the Mitchell review. "A trip to the US at this stage would be an appalling PR mistake", one talks insider said last night.
"Senator Mitchell has made considerable sacrifices for this process, and I think the least David Trimble could do would be to do him the courtesy of staying here for his review. I think the Americans in Indiana would perfectly understand if he had to cancel his lecture."
Mr Trimble flew to London last night. He has speaking engagements at a university in Indiana tomorrow and on Thursday. He then plans to travel to Washington, where on Friday he is due to brief President Clinton's deputy national security adviser, Mr Jim Steinberg, on developments to date in the Mitchell review.
It is understood that Senator Mitchell, as well as British and Irish officials and some pro-agreement politicians, expressed concern that a visit by the UUP leader to the US at this stage of the negotiations could send the wrong signal about the prospects of the review succeeding.
One report suggested that Senator Mitchell had exerted pressure on Mr Trimble not to absent himself from Stormont, but a source close to the senator said that this was not the case.
A spokesman for the UUP leader said that he was reconsidering whether he would fulfil what were described as "longstanding engagements" in the US. However, a senior talks source said last night that he understood Mr Trimble would depart for the US today and leave his Assembly deputy, Sir Reg Empey, in charge of the negotiations.
"My understanding is that Mr Trimble is happy with the way things are going and that he has delegated responsibility to his negotiating team. In the meantime, the talks will keep going, and one shouldn't read too much into his decision," the source said.
Mr Trimble's absence from the talks would suggest that the UUP has arrived at a fixed position on the question of breaking the deadlock over decommissioning and the formation of an executive. His absence might also indicate that the talks are not expected to conclude this week.
Mr Trimble has predicted that there will be a successful outcome to the talks process "sooner or later". A decision by him to visit the US would suggest a conviction that the end will come later rather than sooner.
The UUP and Sinn Fein broke from their talks at Castle Buildings yesterday evening. The SDLP then had further discussions with Senator Mitchell. There was no hint of a breakthrough or any significant progress last night. The parties are due to return to Stormont this morning for further negotiations.
The UUP and Sinn Fein appear to be still deadlocked on the question of an IRA commitment to decommission, which republicans argue is equivalent to a surrender, and a timetable for a start to decommissioning.
While it is understood that Mr Trimble is prepared to have Sinn Fein enter an executive before decommissioning, he wants some form of prior commitment and is insisting that decommissioning should begin within days of the executive being formed.