Mr Blair announced in 2007 that he was leaving the Anglican Church to become a Catholic.
His wife and children were already Catholic and there had been speculation that he would convert after leaving office that year.
In tonight’s BBC interview, Mr Paisley recalls how Mr Blair told him of his plans shortly before he converted.
“I used to meet him in his private room, not so much in his office,” Mr Paisley states in the programme.
“He said, ‘look, I’m going downstairs now and I’ll let you out the back door and you can get away quick’.
“And as we were walking down the stairs he stopped, he looked back at me, and he said, ‘Ian, there’s something I need to tell you’.
“‘When the hands of that clock’, and he pointed to a big clock, ‘when they come to eight o’clock I will be a Roman Catholic.
“And he said, ‘I didn’t want you to leave without telling you. I’d rather tell you myself’.
“And I said ‘you’re a fool’, and I walked on.”
During the interview, Mr Paisley says he spent “a good deal of time” discussing religion with Mr Blair, whose maternal grandparents came from Co Donegal.
Another detail, from the Daily Mail:
In the BBC documentary, Dr Paisley was asked what his reaction would be if one of his own family came home with a Catholic.
‘I would have bought a long cane and have given him a few strokes with it,’ he joked.
But he then added: ‘I would have said “Let us sit down and ask God his opinion on this” and I would have said “Although you hurt me doing what you are doing, you are my child and my love is greater than my hurt”.
‘And they could come in and out of this house as they would, they would not have been put out by me or my wife either. We wouldn’t have liked it but we would lump it.’
Happy Week of Prayer for Christian Unity, y’all.