New Labour leader Ed Miliband does not believe in God, he said yesterday.

Mr Miliband had previously said his religious views were a “private matter”, and his declaration yesterday means two of the three leaders of major British political parties are self-proclaimed atheists. Deputy Prime Minister Nick Clegg also confirmed he does not believe shortly after being named Liberal Democrat leader, while David Cameron last year said religious faith was “part of who I am” but admitted he did not go to church regularly.

The Labour leader’s atheism puts him in stark contrast to his predecessors Tony Blair and Gordon Brown, for whom religion was a central part of their lives.

In an interview on Radio 5 Live yesterday, Mr Miliband was asked by presenter Nicky Campbell: “Do you believe in God?”

The Labour leader replied: “I don’t believe in God personally, but I have great respect for those people who do.

“Different people have different religious views in this country. The great thing is that, whether we have faith or not, we are by and large very tolerant of people whatever their view.”

Mr Miliband and brother David are of Jewish descent, but religion did not play a large part in their upbringing by their Marxist father Ralph Miliband.

David has said publicly he is an atheist, and was the target of some criticism for sending his son to a Church of England school.

Ed yesterday said he believed most faith schools did a “fantastic” job in educating children, but added he thought it best for children of different backgrounds to be educated together. “I’m not going to slag off faith schools,” he said. “I think it is important for people of different backgrounds and faith groups to go to school together. Many faith schools do that.”

Despite spin doctor Alastair Campbell’s famous comment to reporters that “we don’t do God”, Mr Blair has confirmed since leaving power that his religious faith was “hugely important” to his premiership. He said he did not speak publicly about his belief while in office out of fear voters would think him a “nutter”.

Since leaving Downing Street, he has converted to Roman Catholicism, and in his recent memoir, A Journey, he wrote: “I have always been more interested in religion than politics.”

While more private about his personal religious beliefs, Mr Brown left no doubt of the importance of his father’s work as a Church of Scotland minister in shaping his view of life and his political values.

Meanwhile, Mr Miliband declined an opportunity to propose to partner Justine Thornton on live television yesterday, but insisted that their unmarried relationship would not be an obstacle to him becoming prime minister.

Mr Miliband said that he and Justine, 40, would get married “eventually”, but when ITV1 interviewer Kate Garraway suggested he should pop the question straight away, he responded: “I think it’s better to do it in person, really.

“I don’t think it would exactly bring out my romantic side to propose on Daybreak, but thanks for the offer anyway.”

He insisted that voters were “pretty relaxed” over whether or not politicians were married, and said that the important issue was whether a couple provided a stable home for their children.

Mr Miliband admitted he was “really embarrassed” not to have signed his name on the birth certificate for the couple’s first child, Daniel – now 15 months old - and said he would make sure he does so when Ms Thornton gives birth to their second son, due in November.

He told Daybreak: “I have a huge belief in the importance of stable family and I think it is so important to say that.”