Ian Paisley has said he decided to share power with Sinn Féin at Stormont rather than have "the union destroyed and [ the] setting up of a joint government by the South of Ireland".
In his first full interview since the groundbreaking meeting with Sinn Féin president Gerry Adams, the DUP leader said he had agonised over his decision.
He told Radio Ulster yesterday he was repelled by the British and Irish governments' so-called Plan B which entailed direct rule with more Dublin input should the push for powersharing have failed.
"They were going to take us over," he said. "So I think that I had to take a step, a step that I had a lot of heart-searching on, a step that brought me a lot of pain, a step that had to put me out of the class of a coward, into the class of a man that was prepared to sell himself and his reputation, for the sake of his country."
He said of his new working relations with republicans at Stormont: "This is a workable relationship that I have to have, not because I want it but because the undemocratic forces in Westminster forced it upon me." He said he was pushed into taking such a decision which has prompted a series of resignations from his party, including that of party MEP Jim Allister.
"The British government threatened me by telling me . . . every night the secretary of state was threatening me . . . do you think I want to have Plan B?"
He admitted: "I was frightened. I was frightened for my country. I love my country. My father was one of Carson's old Volunteer Force. My father's home in Rostrevor was burned down by the IRA. I have lived and worked and I have been at more funerals across this country than any other minister trying to bring succour and help to people. It goes into my very gut . . .
Addressing Catholics and nationalists he insisted they had little to fear from him as First Minister and joint head of a new administration. "My message to the nationalist people of Northern Ireland, Ian Paisley is not an ogre. Ian Paisley in his political work has never, at any time, turned a Roman Catholic from his door."
Referring to his joint letter with Martin McGuinness to Northern Secretary Peter Hain to quit his offices at Stormont Castle, Dr Paisley said: "He was a man living in our tenancy, he was a squatter, that's what he was and it's the right thing that squatters go out and the real people that own the building take over."
Asked for a guarantee that as First Minister, controversial new water charges would never be introduced, he said: "There will be a solving of this problem if we can achieve what we hope to achieve when we visit the chancellor. He's already made a stagger at it, but the stagger was not good enough for the simple reason that he wasn't given the full facts and of course people have been paying water rates. It seems to me that you shouldn't be asked for water rates twice."