The former Labour Justice Secretary, Jack Straw has attacked the opposition to marriage equality by the Church of England and the Roman Catholic Church.

Mr Straw served as Home, Foreign and Justice Secretary under New Labour. He was Foreign Secretary when civil partnerships were introduced but was absent from the vote, as he was from most LGBT rights legislation.

In the Lancashire Telegraph he writes: “ A central principle common to all world religions is the idea that we should behave towards others in the way in which we would expect others to behave towards us. Christ devotes much of his teaching to this theme, building on the Old Testament injunction that we should love our neighbours as we love ourselves.”

” ‘Judge not, that ye be not judged’, and ‘Do to others as you would have them do to you’, are two of his most powerful, and enduring, messages about how individuals, local communities, and whole societies, should live peacefully, and happily, with others.”

Mr Straw questions if the leaders of British Christianity are practising these essential teachings of Christ.

He writes: “I happen to be, in the modern jargon, ‘straight’. It doesn’t make me a better person.

“I didn’t choose to be straight. It’s how I am. It would be no different if I were gay. I would neither be a better, nor a worse, person because of it. It would simply be how I was.

“Because I am straight, I have a right to marry a woman. But if I were a gay man, or a lesbian woman, in love with another gay man, or lesbian woman, I can get to a half-way house with a “civil partnership”, but the law currently says that I cannot marry.”

The Church of England has said it is “opposed to all forms of homophobia and would want to defend the civil liberties of homosexual people, and to welcome them into our churches” but that it “believes on the basis of Bible and tradition that marriage is between a man and a woman and does not accept that this needs to change”.

The head of the Catholic Church in Scotland compared “grotesque” plans for gay marriage with the reintroduction of slavery.

Mr Straw admonishes them: “Some Church leaders say the law should stay that way, on the spurious grounds that the sanctity and importance of heterosexual marriage will somehow be damaged. How, why?

“I know of no-one who is married who feels threatened by the idea that another couple, same sex, wishes to cement their love for each other by marrying.

“Why should this not be a matter of celebration, rather than of prohibition?”

He ends asking: “How on earth do these church leaders square their present stand with those biblical injunctions about treating others as you would expect to be treated yourself?”