The leader of the Ulster Unionist Party, Mr David Trimble, has accused party members of trying to damage the UUP and of rejecting its democratic view.
Mr Trimble has come under heightened pressure over the decommissioning issue, with threats from some party members that he will face a leadership challenge if he capitulates over demands for a hand-over of Provisional IRA arms before the formation of an executive.
A dissident UUP MP, Mr Willie Thompson, claimed the First Minister will face a motion of no confidence if he allows Sinn Fein into government without substantial decommissioning. "The next three weeks are crucial for David Trimble's leadership of this party and he knows that," Mr Thompson said. "A lot hangs on whether he is prepared to compromise on the stated position of the party on decommissioning, and he will be removed if he departs from it."
He said he believed Mr Trimble's handling of moves to form an executive over the coming weeks was more important than the party's performance in the European election. The mood within the party was "pensive", he said.
While UUP sources confirmed that Mr Trimble was facing a possible leadership challenge, Mr Trimble accused the dissidents of trying to destroy the UUP and he refused to be drawn on a leadership contest.
Commenting on a report in yesterday's Irish Times that anti-agreement unionists were gathering signatures for a special meeting of the Ulster Unionist Council, he said: "I am being backed by the Ulster Unionist Party. I don't need to challenge them. I am not another John Major. There is nothing new in this. We have had this problem ever since last April that there is a segment of the party that won't accept the democratic verdict within the party and within the community.
"Now some of them have reached the point where they are desperate to do damage to the party and we have reason to suspect that others are colluding in this doing and that is a matter we will be looking at more closely when the time comes."
He refused to comment on reports that many of his colleagues did not believe the June 30th deadline for the formation of the executive could be met. He claimed a Daily Telegraph editorial endorsing the UK Unionist leader, Mr Bob McCartney, in the European election was written by people in London "who were not in touch with people in Northern Ireland". He said a vote for Mr McCartney would split the unionist vote and increase the chances of Sinn Fein winning a seat.
UUP security spokesman Mr Ken Maginnis launched a stinging attack on Mr McCartney, whom he accused of being out of touch. "With apologies to Shakespeare, Bob has that sad cast of one who struts and frets his hour upon the stage and then is heard no more. His is a tale full of sound and fury, signifying nothing." Mr McCartney accused Mr Maginnis of making "another bizarre and intemperate outburst".
Sinn Fein candidate Mr Mitchel McLaughlin called on nationalists to maximise their vote and return two nationalist MEPs. His party leader, Mr Gerry Adams, called on both governments to reconvene talks at Downing Street and "get the process back on the rails". He said it was his understanding that the two governments' June 30th deadline for agreement was absolute.
The North's Deputy First Minister, Mr Seamus Mallon, yesterday warned of the economic price the assembly might pay if the deadline is not met. He also urged the electorate to support his party leader, Mr John Hume, in tomorrow's election.