I’m not a fan of David Cameron, but I had given him the benefit of the doubt on the same-sex marriage Bill. My feeling was that he could only have embarked on such a divisive issue (divisive for his party, that is) because he believed passionately in the cause. But Geoffrey Wheatcroft, in a perceptive piece in today’s Guardian puts it down to political ineptitude: it was part of his campaign to de-toxify the Tory party. “Of all Cameron’s own goals”, Wheatcroft writes,

none is stranger than the same-sex marriage bill. Try to set aside the rights and wrongs and look at this in terms of brute calculation of political advantage (and that’s how politicians do view matters, whatever they may say to the contrary). Bear in mind that Cameron’s critics are correct when they say that same-sex marriage was in neither the Tory manifesto (or any other party’s) or the coalition agreement.

To make this clearer, go back 45 or more years, as some of us can, to the famous liberal reforms passed by parliament under Harold Wilson’s government in the late 1960s, on abortion, homosexuality and divorce. I am old enough not only to remember them but to have collected signatures when I was an undergraduate on a petition for the repeal of the existing law criminalising homosexuality, one of my last political activities and for all I know my only good deed.

But although the bills were passed under the Wilson government, they were not introduced by it. They were all private members’ bills. Abortion reform was sponsored by a recently elected Liberal called David Steel, and homosexual decriminalisation by Leo Abse, an eccentric Labour MP (and by another eccentric who deserves to be remembered with honour, “Boofy” the Earl of Arran, a Wodehousian peer who bravely steered the bill through the Lords).

As a result, although the measures were contentious, there was no animosity between parties – or within them, a contrast indeed with this latest episode. So why did Cameron bring in the bill? The answer given by his somewhat diminished claque of sycophantic admirers in the media is that it was part of his mission to detoxify the Conservatives and show they aren’t the “nasty party” any more. In that case he conspicuously failed in his own terms, since more Tory MPs voted against the bill than for it. He has merely reminded us that he is the weak leader of a bitterly divided party.

Wheatcroft’s point is that the Tories were not brought into this world to be ‘nice’. They’re supposed to be competent, he says, and to protect the world for the wilder enthusiasms of the liberal mind. But Cameron doesn’t match up to that elementary requirement — which is why a new poll ranks him just ahead of John Major and Gordon Brown in the competence stakes.