THE Bishop of Oxford last night warned the Government was “playing with fire” by considering same sex marriages.

The Rt Revd John Pritchard hit out at gay marriage plans, saying: “We know what does work, male and female.”

But Prime Minister and Witney MP David Cameron said the move would help “bind” society together.

Bishop John said marriage came from a “creation ordinance”.

He added: “It is God’s primary intention for males and females to live together in that permanent relationship.

“We would be playing with fire in changing that definition.”

Bishop John said he was “fully supportive” of civil partnerships but allowing marriage “wouldn’t add anything” to couples’ rights.

Civil partnerships, introduced in 2005, confer the same legal rights as married couples.

But gay campaigners say there is no reason to distinguish between the two and those of faith want the chance to get married.

The changes would only affect civil marriages – places of worship would be allowed to choose whether to allow same sex marriages.

But Bishop John said: “It is not up to society or the Government to define marriage at will.

“It wouldn’t be able to redefine marriage to include polygamy or bigamy. There is a given about the definition of marriage.”

He spoke after Cardinal Keith O’Brien, the leader of the Catholic Church in Scotland, this week branded same sex marriages a “gross subversion of a universally accepted human right”.

But Mr Cameron said: “I believe in the ties that bind us; that society is stronger when we make vows to each other and support each other. I firmly believe that is true, whatever the sexuality of the couple, so I will back gay marriage.”

But Conservative Banbury MP Tony Baldry said church ministers had not given “compelling reasons” why civil partnerships were “inappropriate”.

Mr Baldry, an Anglican, said: “Marriage is a union between one man and one woman and therefore there is a feeling this is just going to cause confusion.”

Yet Oxford East Labour MP Andrew Smith said there was no “strong case” against same sex marriages. He said: “The commitment and responsibilities of the relationship are surely much more important than the language used to describe it.”

Tanner Efinger, 28, who entered into a civil partnership with Nick West in their home state of California last year, backed the change.

He said: “Growing up, kids see Disney movies and see the Prince and Princess get married in the end.

“When a child sees that, they see marriage as the climax to the relationship.”

Mr Efinger, a manager at Oxford Castle’s Malmaison hotel, said: “It will do a lot for society and same sex equality.”

Cheryl Briggs, chairman of Oxford Pride, said: “I know a lot of people are religious and marriage means a lot more to them. It feels more real to them.”

The Bishop of Dorchester the Rt Revd Colin Fletcher declined to comment as he is advising bishops on the proposals.