On September 14, the party will have an extraordinary general meeting where Mr. Nesbitt, 67, who serves as the health minister for Northern Ireland, will be formally confirmed as the party's head.

Following an argument with party officials last week, Doug Beattie resigned as UUP leader.

The sole party member to submit a candidacy to succeed him was Mr. Nesbitt, who did so until the nomination period expired at 4:40 pm on Friday. Nine Northern Ireland seats have given him the necessary 35 signatures.

Saying he is "very confident" he has the backing of "the vast majority if not all" of the UUP's elected representatives, Mr. Nesbitt expressed his confidence.

"I'm not going to discuss Doug because I know Colum (Eastwood) has made it clear he wants Claire (Hanna) to take over the SDLP, but there's a long-standing tradition in our party that an outgoing leader does not try and influence the party as to who should be the successor," he said, declining to say whether outgoing leader Doug Beattie has backed him.

"I'm more than happy to come back into the role," he continued. In 2012, I had no idea what I was getting myself into, but now I do, and I am sure I can work for the Ulster Unionist Party, its supporters, and the people of Northern Ireland in general."

The former TV journalist turned Strangford MLA will be the first to head the unionist party twice.

Between 2012 until 2017, he served as leader; however, he resigned after an unfavourable outcome in the Northern Ireland Assembly election.

On August 19, Mr. Beattie abruptly announced his retirement from the party, citing "irreconcilable differences" with the officials.

The distinguished Army veteran and member of the Upper Bann Assembly was chosen as the UUP leader in 2021.

Following the UUP's mostly successful showing in the General Election—the party won a Westminster seat for the first time since 2017—Mr. Beattie tendered his resignation.

But in the end, Mr. Beattie resigned due to an internal dispute about the procedure used to choose the party's new MP Robin Swann's replacement in the Stormont Assembly.