Former PM said he never prayed with Bush before the invasion of Iraq, but he did pray with the Salvation Army

Tony Blair never did pray with George Bush before the invasion of Iraq, he said on Tuesday. "It wouldn't have been a wrong thing, but it didn't happen", he told Charles Moore, the former editor of the Daily Telegraph – answering the question he had refused to answer when it was put to him by Jeremy Paxman and he was still prime minster. But he did pray with the Salvation Army, he said, when he was leader of the opposition despite the horror of some of his staff.

At a debate with Rowan Williams, the Archbishop of Canterbury, he told the audience of 450 people in Westminster, central London: "I remember the Salvation Army coming to see me when I was leader of the opposition.

"At the end of it, she said: 'We're all going to kneel in prayer'.

"There were two members of my office, who should remain nameless, who looked aghast.

"I said: 'You'll have to get on your knees'. One of them said: 'For God's sake' and I said: 'Exactly'".

Blair, who converted to Catholicism to join the same faith as his wife Cherie, added: "One of the things I loved about meeting such people in office was their unashamed proclamation of their faith."

At the debate Blair was funny, and sometimes self-deprecating: "I once wrote a pamphlet about why a human rights act in Britain would be a thoroughly bad idea – then, as prime minister, I introduced one" .

Even in this politician's afterlife, his religious beliefs had a vagueness about them. He was challenged from the audience about his belief in the resurrection and while he was clear that he believed it, it was not at all clear what he meant. "My father was and remains a militant atheist" he said. "So it's a debate I am well familiar with.

"For me the resurrection in the sense of someone reborn is a very important, indeed essential part of Christian faith. Rather than see this as part of a debate about physiology or biology, I see it was what it tells us about human condition."

The former prime minister was speaking at a debate with Rowan Williams, the Archbishop of Canterbury, and Charles Moore, Lady Thatcher's biographer and, like Blair, a convert from Anglicanism to Roman Catholicism.

Challenged by Moore as to why he called Islam a religion of peace when no one would feel it necessary to call Methodism "a religion of Peace", Blair replied that there were times in Christian history when you would have doubted that Christianity, too, was a religion of peace. Yet he believed that religion and democracy should grow together.

"How do we create a situation in which every religion has its truth claims reconciled with the existence of different ones? I believe there is a simple and obvious way to do this – to recognise it would be very arrogant towards God's purpose for us, not to recognise that others have their own ideas."

Williams rephrased the argument slightly: "A lot of religious people assume that they have to win God's arguments for him. That seems to me a preposterous religious position to be in." Blair suppressed a giggle of recognition.

But when it came to actual practical clashes between religious and political beliefs, the panel talked about gambling rather than sex or even assisted dying. Williams recalled the Lords debate in which the Blair government's plans for supercasinos had been defeated. "The idea that you could regenerate an impoverished corner of Manchester by importing a supercasino seemed to me utterly utterly bizarre."

"We are in danger of assuming that morality is self-evident, that there is a default morality which is secular and that what religious people think is just a decoration."

Blair was unrepentant. Although he was anxious for religious groups to make their voices heard, democracy, for him, meant that elected politicians would listen, and then do what they wanted anyway: "I didn't agree with the Salvation Army position on gambling. If people could already gamble online, so I didn't see why they should be stopped from doing so here. [And] In the end, I as prime minister should decide what was best for the country."

Williams was more thoughtful about the limitations of his power. Talking about women bishops, where his proposals for a compromise to soothe the feelings of the defeated opponents had been rejected by the church's general synod, he said: "The bishops – myself included – have had to learn just how difficult it is for women to hear an all male body pronouncing on their future. I still think myself that we had the right general idea, but that's not going to make much difference."