Tensions within David Trimble's Ulster Unionist Party are continuing following the resignation from the party last week of prominent dissident Jeffrey Donaldson and two fellow elected members of the Belfast Assembly.
The decision of Mr Donaldson to quit, and possibly join the Ian Paisley's Democratic Unionist Party, has changed the balance of Unionist politics.
Ulster Unionist Party president and fellow Westminster MP Martin Smyth has warned he could also be forced out of the party at its annual meeting in March.
He said Mr Trimble should announce he will be standing down as party leader by the time the meeting takes place.
A meeting of party officers this afternoon discussed Mr Donaldson's letter of resignation.
The South Belfast MP said he detected ``a sense of joy'' among some party officers over Mr Donaldson's decision to quit the party after an effective ultimatum from its executive to toe the policy line.
But he added: ``I would think there is still a way back for Jeffrey but I am not sure he would want to take it.
``If he decides to join the DUP in January, and he has not said he will, then I cannot see him coming back. But if he does not then he could come back possibly after the March meeting.''
Mr Smyth said he hoped to hear the responses to the Donaldson departure from other party officers.
``It could also be that the party council or executive decides they want to dispense with my services also. But I will not be resigning,'' Mr Smyth added.
But David Burnside, the third MP who resigned the Ulster Unionist Westminster whip over the British and Irish Governments' Joint Declaration proposals, said he believed Mr Donaldson had made a ``tactical mistake'' in resigning.
The departure of the three Assembly members puts the UUP on equal footing with Sinn Fein. If they join the DUP, the UUP would be nine seats behind the DUP.
Ulster Unionist leader David Trimble rejected claims by Ian Paisley that the UUP now represented only a ``rump'' of unionism because of its reduced Assembly strength.
Trimble argued: ``Questions like this are all academic.
``There is no prospect of the Assembly meeting. It would be a bold person who would try to identify when and whether this Assembly will meet.
``There is a broader issue here. It is clear from meetings in Downing Street this week that the DUP do not have a magic plan. The most likely thing we're looking at in the future is a long period of direct rule.''