Tony Blair held back from converting to Catholicism until after he quit as prime minister because of the "palaver" it would have caused to do it while he was in office, it was revealed today.
In an interview about his religious faith to be broadcast on Sunday, Mr Blair insisted that his conversion did not amount to a rejection of the Church of England and its teachings.
And he batted away suggestions that he may have held off from converting earlier in his life from fear that Catholicism would exclude him from the highest political office.
Mr Blair was reticent about discussing his faith while in office - his spin-doctor Alastair Campbell once famously commented that "we don't do God" and the former PM himself said he feared he would be viewed as a "nutter" by voters if he spoke about religion.
But in his interview for BBC1's Christmas Voices he expresses regret that he was not more "adventurous" and says it should not be the case that politicians have to be inhibited about talking about God.
"People, in one sense, are a little comforted if they think the person leading them has some sense of spiritual value," he said. "Probably we could have been a little more adventurous on this without bringing the house down."
Mr Blair left little doubt that it was fear of the public and media reaction that led him to delay his conversion until after he quit as PM - even though he had been attending mass for 25 years and was bringing his children up as Catholics.
"It would have caused such a palaver if I had done it whilst I was still in office," he said.
"There was no disrespect... for the Anglican church, it's just that my family all go to mass, my kids are brought up as Catholic and I have been going to mass for 25 years, so to come into full communion seemed to me my natural home.
"There is no great... doctrinal dispute I have with the Anglican church... It wasn't about that at all, it was a very personal decision."
No Roman Catholic has ever been Prime Minister, and there have long been suspicions that Mr Blair remained in the Church of England in order to avoid placing an obstacle in his way to Downing Street.
But asked about why he did not convert earlier in his career, he replied: "Maybe I was at a slightly different stage of my own development... I hope we're not in a situation where you couldn't have a Roman Catholic as Prime Minister.
"I don't, to be honest, think it makes any difference to people at all, politically."
Describing his own faith as "the foundation of your life", Mr Blair said he thought it "sad" that as Prime Minister he was unable to talk openly about it.
He added: "Maybe I became too sensitive to that or too cautious about it, but I just came to the conclusion that if I started talking about religion it was going to be difficult."
Since leaving office, Mr Blair has established the Tony Blair Faith Foundation with the aim of increasing understanding between the world's major religions.
In this weekend's interview, he said he was driven by the belief that "by understanding the others' faith, you do actually learn to respect - not tolerate but respect - the other".
"My view is where there's ignorance there's fear and where there's fear there's conflict," he said. "By contrast, where there's understanding there's more likely to be harmony."
Mr Blair's interview can be seen on Christmas Voices on BBC1 at 10am on Sunday.