When Tony Blair was Prime Minister, his officials warned him not to end one of his speeches with the words “God bless Britain”.
Po-faced advisors told him “this is not America” and persuaded him to drop the idea, the Daily Mail reports.
Mr Blair told the story at a conference organised by Holy Trinity Brompton, a large Evangelical Anglican church in London.
He said: “You know the American president finishes an address to the American people by saying ‘God bless America’.
“I had the idea of finishing my address by saying ‘God bless Britain’. This caused consternation in the whole system. A committee was convened, and we had to discuss it.
“I remember we had this debate on and off but finally one of the civil servants said in a very po-faced way ‘I just remind you Prime Minister, this is not America’ in this very disapproving tone, so I gave up the idea.
“I think it is a shame that you can’t since it is obviously part of what you are.”
But Mr Blair warned: “I think God and religion can also be abused by politicians too so you have got to be careful.”
He also recalled an incident from his childhood, when his schoolmaster offered to pray with him for his sick father.
Mr Blair said: “I remember going to school that day not knowing whether he was going to live or not.
“The headmaster of the school called me into his study and he said, ‘I think we should kneel and say a prayer for your father.’
“I said to him, ‘I should tell you my father does not really believe in God.’
“I will never forget what he said to me – he just said to me ‘but God believes in him, so let us kneel and pray.’ That made a big impact on me.”
During his time as Prime Minister his official spokesman, Alistair Campbell, famously said “we don’t do God”.
The current Prime Minister, David Cameron, has been more forthcoming in his willingness to praise the place of Christianity in the nation’s life.
But he has also sparked a damaging row with churches and other religious groups by attempting to redefine marriage.