When dads hit the dance floor trying to be hip and trendy, everyone else cringes with embarrassment. It's the same with David Cameron's modernising push for gay marriage. A new poll of LGBT people reveals that almost two thirds flinch at his motives. They think he is pushing the policy for the politics, rather than the principle. He's trying to look hip and trendy, but he just looks fake and phoney. He's a disco dad.

Even supporters of gay marriage cringe at his dance moves. Blogger Iain Dale thinks the proposals are a far cry from direct 'equality' because matrimonial law will continue to have rules about consummation for straight couples, but none for gay couples. Mr Dale suggests the government did not want a bill that spelled out a precise definition of gay sex. He also points out that gay couples and straight couples will be treated differently when it comes to the laws of adultery.

Gay rights campaigner Peter Tatchell also thinks the proposals don't achieve true equality. Under the government's bill, a gay couple will have the option of a civil partnership or a gay marriage. But straight couples will only have marriage. There are some straight couples campaigning for the right to enter a civil partnership, and they're pursuing a claim of discrimination to the European Court of Human Rights. We all know that the judges in Strasbourg are capable of doing anything. By the way, if civil partnerships are opened up to straight couples it could cost the UK taxpayer £5billion because of the associated tax implications.

Given that David Cameron's plans for gay marriage appear to be making all sides cringe, who's pushing him onto the dance floor? Westminster insiders say it is his wife, Samantha. She comes from an aristocratic family of the metropolitan artsy variety, rather than the country horse and hounds variety. She's known to have socially liberal views, so much so that Government ministers have joked she has more of a liberalising influence on her husband than his coalition partner Nick Clegg. The prime minister's mother, Mary, was asked why her son is pushing a policy which is alienating so many traditional Tory voters. She replied, "I know. But David just won't be told."

Embarrassed by seeing their leader trying to bop like a teenager, party activists are leaving in their droves. Membership has plummeted by more than half since he became leader, and over 70 per cent of remaining members believe the issue of gay marriage is tearing the party apart. But it's not just the foot soldiers who are quitting. Experienced local association chairmen have quit too. We're talking about people with years of experience who have been faithful to the Party for decades. No leader of any organisation can afford to lose people like that.

But perhaps David Cameron thinks he's dancing to a different tune. He's not trying to appeal to his party, he's not even trying to appeal to the gay vote. He's trying to win those voters who are attracted by the hip and trendy metropolitan values. Ultimately, he is hoping that his disco-dad moves are a vote-winner. It's not working, according to polling which shows gay marriage could cost him 1.1million votes and up to 30 parliamentary seats. Much of that support is now going to Ukip, which has recently overtaken the Lib Dems as third most popular party. Gay marriage is a prime factor.

So while David boogies to the beat of redefining marriage, spurred on by his wife, the rest of the country collectively winces and shakes its head. It's time this disco dad got off the gay marriage dance floor, before he gets pushed off.