Mr David Trimble and Mr Jeffrey Donaldson will come face to face in another confrontation in Belfast tomorrow as the Ulster Unionist leader proceeds with his action to expel the Lagan Valley MP and his two Westminster colleagues, the Rev Martin Smyth and Mr David Burnside, from the party.
Mr Trimble is still intent on forcing the MPs out of the party, and the three MPs are equally intent on forcing him to take such action, believing that it could further jeopardise his leadership position, sources from the two camps told The Irish Times.
The first moves towards that end will begin at an emergency meeting of the UUP's party officers in Belfast tomorrow, called by Mr Trimble.
There are 14 party officers, two of whom are Mr Donaldson, a party vice-president, and Mr Smyth, the party president.
Sources said Mr Trimble would test the party mood by asking party officers whether they supported his leadership tomorrow.
The Rev Smyth, who is refusing to resign as president, said he would not be at the meeting because of Westminster parliamentary business.
In a defiant statement he said he had no regrets over resigning the whip.
Mr Donaldson, however, said he would attend, and would resist any attempt to discipline him and his colleagues.
"If David Trimble goes down the road of pressing for disciplinary action, of removing people from office, or throwing people out of the party, then he really has lost touch with reality."
One of the concerns of Trimble supporters is that the so-called grandees of the party, some of whom are party officers, tired of all the in-fighting, could advise Mr Trimble to resign.
One of these senior figures and a party vice-president, Lord Maginnis, said he was standing behind Mr Trimble and was severely critical of the three MPs.
One of the four honorary secretaries, Lord Rogan, also a perceived grandee, could not be contacted yesterday, but according to sources he was also remaining loyal to Mr Trimble.
MEP and a party vice-president, Mr James Nicholson, who according to Mr Ken Maginnis was one of the "grey suits" who told the then UUP leader Mr Jim Molyneaux eight years ago that it was time to make way for a new leader (Mr Trimble), was more hesitant in his response.
Asked was he prepared to support Mr Trimble, he replied: "As far as I am concerned at this stage I am making no comment. Things are at such a fluid state in the party after what has happened it would do well for many people in the party to step back and reflect on what the situation is."
"It is too early to look at that," he told The Irish Times from Brussels when asked should Mr Trimble now consider his position as leader.
"He has just come through and did win another situation in the Ulster Unionist Council. We have to wait and see what plays out."
Despite the tensions and uncertainty, party sources said that Mr Trimble was in combative mood, and determined to resist the challenge from the three MPs.
DUP MP Mr Nigel Dodds said the UUP was imploding, and that elections must be called.
"It is time for the government to realise that no sustainable progress will be achievable until the people of Northern Ireland have been able to deliver their verdict at the polls. The days of the 'Save Dave' campaign are over."
Former SDLP minister Dr Sean Farren last night called for a "greater sense of solidarity between the pro-agreement parties to overcome the present impasse".