Outspoken Ulster Unionist Basil McCrea has said he is confident of being vindicated by a party disciplinary hearing due on Friday.
The internal meeting in Belfast will focus on the Lagan Valley Assembly member's stance in regard to the Union flag crisis.
Mr McCrea's day of reckoning with party officials has already been postponed twice since he had the whip removed last month.
UUP leader Mike Nesbitt took the disciplinary action after Mr McCrea criticised the party's handling of the flag issue.
Ahead of the meeting at party headquarters, Mr McCrea said: "I feel I have a strong case and I am looking forward to the opportunity of making it."
The MLA said he had also declined a request to keep details of the meeting private, insisting that the public had a right to hear what had happened.
The controversy first flared when Mr McCrea described as a "stupid idea" a joint attempt by the UUP and DUP to get the Assembly Commission to examine whether the flag should be flown more regularly at Stormont.
Mr Nesbitt accused his party colleague of having an "inability to exercise self-discipline" or be a team player. He claimed he was doing "enormous damage" to the UUP.
However, Mr McCrea has insisted his views are consistent with past UUP policy on flags.
Last week, Mr McCrea voted against his party in the Assembly. He refused to support a DUP amendment to a UUP motion that deleted a reference to the Good Friday Agreement.