Former Ulster Unionist leader Mike Nesbitt may try to take McDonnell's Westminster seat in South Belfast
Former Ulster Unionist leader Mike Nesbitt could make a pitch for a Westminster seat, according to senior party sources.
In a surprise move, the UUP is considering running Mr Nesbitt in South Belfast and moving Danny Kennedy to Upper Bann.
Party insiders said they believed that their former leader would be a "very credible candidate" in South Belfast who would strongly appeal to both unionist and non-unionist voters.
Mr Nesbitt lives just outside the constituency, which is regarded as the most liberal in Northern Ireland.
Sitting SDLP MP Dr Alasdair McDonnell was re-elected in 2015 with just 24.5% of the vote, the lowest share of any candidate ever returned to the House of Commons.
Although the UUP also ran in the election, the DUP's Jonathan Bell came in just 900 votes behind Dr McDonnell (below).
A unionist unity candidate would be in a strong position to take the seat.
Until now speculation has centred on the DUP's Emma Little Pengelly, who lost her South Belfast Assembly seat last month, as the most likely agreed candidate to emerge from pact negotiations.
However, UUP sources last night said that Mr Nesbitt's name had emerged from its own internal discussions as the party's most likely candidate.
"Since Theresa May called the snap election on Easter Tuesday we have held a series of meetings and it has been agreed that Mike would be a very strong candidate in South Belfast," a UUP insider said.
"He already has associations with the constituency. There is a solid unionist vote in South Belfast and Mike could make gains beyond that too. He is capable of winning support among Alliance and nationalist voters."
The UUP has had a low profile in the constituency since the departure of former Stormont Health Minister Michael McGimpsey, and the DUP is the biggest party in South Belfast.
But Mr Nesbitt's broad appeal could make him the most dangerous unionist unity candidate for Dr McDonnell. Although he believes the Brexit referendum result must be implemented, the former UUP leader was a Remain supporter.
Mr Nesbitt's support for abortion to be permitted in cases of fatal foetal abnormality and rape could also strike a chord in a constituency with strongly liberal views on social issues.
If the former UUP leader was successful in any Westminster bid, he would have to resign his Strangford Assembly seat.
Until now it had been predicted that Mr Nesbitt would most likely go to the House of Lords, but sources said he wants to remain in elected politics.
Mr Nesbitt resigned as UUP leader seven weeks ago on the day of the Assembly election count. His personal pledge to give his second preference vote to the SDLP was blamed for losing the party votes.
Although former UUP deputy leader Danny Kennedy lost his Assembly seat in Newry and Armagh last month, he was still expected to contest that constituency in June's Westminster election.
As the unionist unity candidate there in 2015, he secured 16,000 votes - 4,000 behind Sinn Fein's Mickey Brady.
UUP sources said there was no realistic prospective of a unionist taking Newry and Armagh from Sinn Fein so internal discussions had taken place about parachuting Mr Kennedy into neighbouring Upper Bann.
The party hierarchy had been keen to run him there in the 2010 Westminster election but he eventually opted to remain in Newry and Armagh.
However, UUP sources said there was a "very real possibility" that a move could be on the cards now. A traditional unionist and Orangeman, Mr Kennedy is firmly on the party's conservative wing.
Jo-Anne Dobson, who lost her Assembly seat last month, may also consider seeking the UUP Westminster nomination for Upper Bann.
However, regardless of whom the party selects, it seems very unlikely that the DUP would sacrifice its sitting MP David Simpson in any unionist pact.