‘Only signage will change’

He also hinted another high profile name would be joining him and John McCallister in their stance.

In an interview with the Star he said: “My intention is to carry on representing the people as best I can. My office will remain open, staff remain employed, indeed the only thing that will change is the signage above the door.”

He went on: “I’m not a shrinking violet in saying what I believe in. I have no doubt the people of Lagan Valley knew what they were voting for and I am the same person today as I was then.

“On a practical basis in a multi-seat PR constituency it is not possible to resign and stand in a by-election, in fact if you resign you do not have a by-election you have a party appointee. However, I absolutely intend to face the electorate at the soonest possible opportunity. I don’t under-estimate the challenge that presents me with but I believe in what I said and what I stand for.” He said it was not decided yet what form any new party would take but it would be pro-union, non-sectarian and would work for a better Northern Ireland for everyone.

He pointed to the Westminister model of the loyal opposition holding the Government to account.

Of his decision to resign he said: “It is about policy. I have stated repeatedly both internally and externally I do not believe unionist unity is good for the people at large.”

And of the upcoming by-election he predicted the combined unionist vote would decrease while Sinn Fein’s vote would increase: “The more problematic issue for the whole of Northern Ireland is it will become a bitter sectarian dog fight full of emotion which could, potentially, drag Northern Ireland back to the terrible days of the Troubles.

“I do despair of so called political leaders who cannot see having a short term political advantage will be a long term strategic mistake.”

Mr McCrea signalled his intention to part company with the UUP after the DUP and Ulster Unionists agreed to field a unity candidate in the upcoming Mid-Ulster by-election.

During an interview on the BBC’s Nolan Show on Friday, Mr McCrea confirmed his intention to resign from the party following the official announcement that victims campaigner Nigel Lutton, son of a murdered RUC Reservist, would contest the Mid-Ulster by-election as a Unionist unity candidate.

Already at odds with his party over his stance on the Union Flag row, Mr McCrea told Stephen Nolan there was clearly no place in the UUP for individuals such as himself and Mr McCallister - both opposed to Unionist unity and ‘narrow expressions of Unionism’ - and he had no confidence, he said, in the assurances of party leader Mike Nesbitt that the Mid-Ulster decision was in response to specific circumstances and in no way indicative of any move towards Unionist merger.