A UUP MLA could face a party sanction over his support for the flying of the Union flag on designated days only.
Three Belfast councillors – David Browne, Jim Rodgers and Bob Stoker – want Basil McCrea disciplined for rowing in behind the Alliance Party motion.
And the trio have made it known that they will consider their positions within the party if McCrea is not brought to heel.
During an interview for BBC Radio Ulster on Friday morning, Mr McCrea said the flying of the union flag was a matter for Belfast council.
However, he agreed it should fly only on designated days.
Cllrs Stoker, Browne and Rodgers the Lagan Valley MLa has contradicted party leader Mike Nesbitt and is not upholding the party’s constitution in support of the union.
Mr Stoker said he and his council colleagues are seriously considering their position and want the party to deal with Basil McCrea as a matter of urgency.
The councillors felt others had been dealt with ruthlessly while Mr McCea was an unguided missile who had been let off.
In a statement the UUP said: “Mike Nesbitt made the Ulster Unionist party`s position absolutely clear on Thursday.
“There is a fundamental issue regarding the chipping away of people’s identity as British citizens.
“No doubt Basil McCrea’s interview will be brought up when the party executive meet tomorrow.”