He once denied that he had prayed with former US president George Bush - but on Tuesday Tony Blair admitted he once ordered members of staff to do just that.
The former prime minister, taking part in a debate on the role of religion in public life alongside the Archbishop of Canterbury, said he had done so despite the now-famous instruction from press secretary Alastair Campbell that: "You don't do God".
Tony Blair did pray with staff, he admitted to an audience at a faith debate
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."
Asked by former Daily Telegraph editor Charles Moore, also taking part in the last of the Westminster Faith Debates, about why he did not pray with Bush - as Jeremy Paxman questioned in a Newsnight interview - Blair replied: "It wouldn't have been a wrong thing.
"It's just that it didn't happen. I'm sure that as a journalist you understand the distinction."
Blair said it was vital that fellow Christians were not embarrassed about talking about their faith.
He told the audience at Central Hall: "I think it's very important that we are prepared to speak up and speak out from a position of faith, that we're not afraid to say 'This is why we believe what we believe', and not be embarrassed about it or think there's something strange about saying it."
Asked by a female rabbi in the audience about the issue of women bishops, Blair declined to give his own viewpoint.
He said: "I think this debate will carry on within the Jewish tradition, within the Christian tradition and other traditions, but I think in the end it's a matter of where people stand and what they think about it."
(Left to right) Tony Blair, Charles Moore and Archbishop Rowan Williams
Blair, who set up the Tony Blair Faith Foundation, said he believed "very passionately" in the importance of "reaching out to people who are of a different faith to our own".
He added: "I find it an interesting thing, that I find a connection with people who are of faith, even though they're of a different faith to my own, precisely because there is a certain space, philosophically and emotionally, you can congregate around."
Asked if there was any religious group he would not consider meeting with, he said: "I'm pretty broad-minded. I guess there might be.
"Inevitably in these situations there's an element of subjective judgment - some may sit on the further shores of common sense that you don't dialogue with."
Blair denied that the gift of a King James Bible to every school was "trying to convert anyone" and said of the book: "It's part of a tradition in this country."
That was echoed by Rowan Williams, who described it as "an iconic gesture" and one that was important educationally.
The pair have clashed in the past over the issue of gambling, which the Archbishop referred to during Tuesday's discussion.
Blair reacted with a wry smile as Dr Williams said: "I did think that the idea you could regenerate an impoverished area of Manchester by bringing in a super casino is utterly, utterly bizarre."
The audience applauded as he added: "And I've not changed my mind."
When Blair had answered the question, he said he still agreed with casinos being set up in a world where online gambling takes place.
Blair said politicians should not ignore religion, calling for a "religion-friendly democracy and democracy-friendly religion".
It is "completely justifiable" for people of faith to set out their views from a religious standpoint, he added.
The former prime minister also said it was "very arrogant" for people to not recognise others of different faiths.
He said: "When people come together across the faith divide, they don't give up their own faith but they start to understand there are many things we share."
The debate was hosted by former home secretary Charles Clarke and Linda Woodhead of the Religion and Society Programme at Lancaster University.
Think tank Theos, the Arts and Humanities Research Council and the Economic and Social Research Council also supported the series of talks, which has included appearances by Attorney General Dominic Grieve and atheist Richard Dawkins.
About 40 protesters from the Stop The War Coalition chanted slogans outside before tonight's debate started, and they could be heard inside the hall.
Spokeswoman Lindsey German said: "It's fairly clear that Blair is trying to make a political comeback and we think people shouldn't forget what happened in Iraq and what his role in the war was.
"There's something obscene about a man who does have blood on his hands sitting in a pleasant environment with the Archbishop of Canterbury discussing finer points of faith.
"I respect everyone's right to religion and beliefs but I don't know how Blair can profess to have Christian faith and behave in the way he has behaved."
Earlier on Tuesday, Blair gave an interview to the Daily Telegraph in which he said Britain must not "hang bankers at the end of the street" in response to the financial crisis as he admitted partial responsibility for failing to prevent the crash.
The former prime minister added that while his government failed to regulate the financial sector properly it would be wrong to let the state intervene too much in the City.
''We must regain the basic values of what society is about,’’ he said. ''We’re not against wealth, but we are in favour of social responsibility.’’