On the eve of the Conservative Party conference, David Cameron’s refusal to support same-sex civil marriage looks increasingly isolated and out of step, argues human rights campaigner Peter Tatchell.

He is ignoring the growing calls for marriage equality from senior figures within his own party and from his Liberal Democrat coalition partners, the Labour opposition and the wider public.

He is the only major party leader who is not yet supporting marriage equality. His deputy prime minister, the Liberal Democrat leader Nick Clegg and Labour leader Ed Miliband back marriage for gay couples. London mayor Boris Johnson is in favour, as is Margot James MP, until recently the Tory party vice-chair. [Note- Mr Cameron wrote on PinkNews.co.uk: "I want to do everything I can to support commitment and I'm open to changing things further to guarantee equality."]

Cameron’s opposition to lifting the ban on gay marriage calls into question the sincerity of his professed pro-gay credentials. Nearly two-thirds of the public reject his support for the status quo, which bans gay couples from getting married in a registry office.

A Populus poll in June 2009 found that 61 per cent of the public believe that: ‘Gay couples should have an equal right to get married, not just to have civil partnerships.’ Only 33 per cent disagreed.

The tide is turning in the UK in favour of same-sex marriage. It is also a growing trend all over the world, from Canada to South Africa, Portugal and Argentina. Why can’t we have marriage equality in Britain too?

Some people say that civil partnerships are sufficient for gay couples. This is hypocritical. They would not accept a similar ban on black people getting married. They would never agree with a law that required black couples to register their relationships through a separate system called civil partnerships.

It would be racist to have separate laws for black and white couples. We’d call it apartheid, like what used to exist in South Africa. Well, black people are not banned from marriage but lesbian and gay couples are. We are fobbed off with second class civil partnerships.

Civil marriage in a registry office should be open to everyone without discrimination.

In a democracy, we are all supposed to be equal under the law. The Con-Lib coalition’s professed commitment to gay equality cannot be taken seriously while it upholds the ban on same-sex marriage.

Note: During the general election campaign, the chancellor George Osborne promised to consider the case for gay marriage.

Peter Tatchell’s work is supported by the Peter Tatchell foundation.