Embattled UUP leader Tom Elliott has apologised to nationalists and republicans offended when he described Sinn Fein supporters as “scum”.
Mr Elliott’s outburst came during a speech at an election count on Saturday.
He has said he was provoked by republicans who were shouting and waving tricolours.
In an interview recorded for the BBC he said: “I will certainly apologise to all those good nationalists, republicans, even Sinn Fein voters who felt offended by it.
“It was certainly not directed at them so if they took offence at it, yes, I regret that.”
Mr Elliott also stressed he had not thought of resigning and said none of his Assembly colleagues had called upon him to do so.
News of the apology comes too late to avoid the devastating blow landed on the beleaguered leader by a former senior party member who yesterday snubbed an opportunity to rejoin the party.
Tomorrow morning David McClarty will register in the Assembly as an independent, reducing the once mighty UUP to a single ministry.
And the veteran MLA has described the Ulster Unionists as “not a party per se” as he slammed its election organisation.
Mr McClarty’s remarks will pile further pressure on Elliott with speculation that he will face a leadership challenge.
An emergency meeting of the UUP Executive has been called for Saturday morning in a Dungannon hotel.
A UUP AGM will then be held on June 4 and some members are considering nominating Basil McCrea, the Lagan Valley MLA who stood unsuccessfully against Mr Elliott in last September’s leadership contest.
Others in the party argue that a challenge should be delayed for some months so that other candidates can come forward.
Mr McClarty, a moderate, cited Mr Elliott’s “scum” outburst last week as one reason he was not rejoining the UUP but also launched a devastating attack on the party’s structures.
The veteran East Londonderry MLA was deselected by his constituency last year after its chairman Norman Hillis described him as “toast” and “a spent force”.
In the election Mr McClarty won the seat and the two candidates nominated by the association were defeated.
Over the weekend Mr Elliott made an appeal for Mr McClarty to rejoin the party. His support is crucial because, under the d’Hondt formula, his vote would allow the party to claim two ministries instead of one.
Now that he has refused the second ministry will go to the Alliance party instead.
Mr McClarty said he had rejected the UUP for a variety of reasons. “Tom’s comments were an obstacle but not the main obstacle because I already had a number of really deep concerns about the rules and regulations of the party,” he added.
Mr McClarty compared the UUP unfavourably to other parties like the DUP.
He said: “There is real central control in other parties. Real discipline has been demonstrated by the DUP.”
“The UUP is not a party per se. It’s an amalgamation of 18 different constituency associations. Literally a handful of individuals were able to hold the party to ransom,” he added.