Boy oh boy. Anyone feeling a little down about Opposition Leader Tony Abbott looming over the horizon blocking the sun should pull up a deckchair, pop the corn and watch the show in the UK. Here, tonight, with a farcical mess around voting on same-s-x marriage, British PM David Cameron has confirmed he is one of the worst leaders of the party in modern times.

Last week he managed to stuff up the European Union issue, with 100-plus Conservatives voting against the Queen’s speech. Tonight same-s-x marriage, taken up as a way of colonising Liberal-Democrat votes, has become a huge negative, fuelling the practical civil war between Tory leadership and grassroots (hedgeroots, I guess, it being the shires ‘n’ all).

Last week’s EU vote was complicated enough: a private member’s bill expressing disappointment with the lack of commitment to an in-out EU referendum before 2015, headed off by a bill from the government committing to having a bill authorising a referendum in 2017. Pure shadow play.

Tonight’s gay marriage manoeuvre made that look like the storming of the Winter Palace. Dave had committed to same-s-x marriage legislation last year, even though it hadn’t been in the 2010 election manifesto, and there was no doubt that a large majority of the party membership was against. The promise was made in happier times, when the Con-Dem government wasn’t on the back foot over an absent recovery, a housing crisis and a firestorm over open immigration channels, and E-e-e-e-u-rope. By April, it was clear the government didn’t need the extra grief, and so same-s-x marriage was left out of the Queen’s speech* — thus of course becoming a source of extra grief.

Now, with Cameron weakened, his enemies have seen a fresh opportunity to humiliate him, with a new amendment to the same-s-x marriage act going ahead at the moment. The amendment did a curious thing: rather than go head-to-head against gay unions, it wanted to extend things the other way. The amendment proposed to extend the civil union arrangement that had been made available to same-s-x couples years ago to heteros-xual couples as well. That was an elegant move — who could object to it? It expanded choice for everyone. It also removed the tricky problem that, were same-s-x marriage to be ratified, same-s-x couples would have more options than straight couples, being able to full marry, or to go with a more minimal commitment/union arrangement. Eventually, that would have been challenged in the courts and overturned.

However, one problem for the government with that new arrangement is that it may appeal to many of the several million couples who are cohabiting but not married. They, as de facto couples, remain excluded from a whole series of pension provisions, deductions and business expenses allowances, which they would suddenly come into if civil unions became an option. It would only take a proportion of them to decide that civil union was acceptably non-patriarchal, statist-familialist, heavy, man, to be worth signing up for, for there to be a 4 billion pounds-plus blowout in state obligations.

Where did that 4 billion pounds come from? Exhaustive and costed research? Hahaha, actually the Department of Work and Pensions said that it was a figure they had provided for “illustrative” purposes — that is, pulled out of nothing. The “equalities” minister — imagine how the shires grind their teeth at the Tories having a Swedish-style Equalities Minister — refused to support an amendment extending equality, which upped the contradictory nature of the whole thing. On Twitter, gay campaigner Peter Tatchell urged support for the amendment, noting that his long-term campaign for same-s-x marriage had always been undertaken in the knowledge that he would rather be campaigning for the full disestablishment of marriage, and now that something like that was here, what were you going to do?

“Cameron, now looking like a rather hapless PR goon, may make the history books yet …”

Labour had initially said it would abstain from voting on the amendment — in tribute to the fact that the amendment, while worthy, would slow the ultimate passage of the bill. Last night, the Tory leadership came to them, desperate, saying that backbench Tory support for the amendment — i.e., opposition to same-s-x marriage — was sufficient to get it across and thus sink the whole bill. Labour could have toughed it out, insisted that the government could still advance the bill if it really wanted to, even encumbered with a costly amendment … but Labour eventually agreed to vote it down to get the larger bill through.

The politics of this are head-shakingly complex, but they all revolve around appearance and projection. The Cameroons/Notting Hill Billies around Dave, et al, appear to have cooked up support for same-s-x marriage when they wanted to go to war against their grassroots. Perhaps they still do. Now I suspect they want to get it off the books. The Lib-Dems want to get it through and claim it as a government achievement. Labour want to claim it for one audience, but minimise it for another — old, blue Labour, who are drifting towards the UK Independence Party.

But this vote is only one of the Tories’ worries this week. For in the lead-up to it, a “senior advisor” to Cameron was reported to the papers as saying that Dave was beleaguered by the party membership who were “swivel-eyed loons”. The venue of the remark was soon traced to the Tory-favoured Blue Boar restaurant — couldn’t make it up — in Westminster, and soon accusations were flying at Cameron-chum Lord Feldman, chairman of the Tory party.

“Lord” Feldman is, of course, some upper-middle class joker who was at Brasenose College, Oxford, with Cameron and helped him plan the May Ball (true!), now, after a career in the family fashion business (i.e., sweatshops elsewhere), elevated to the Lords and chairing the Tories. Feldman is one of a number of old Etonians, Bracenosians, etc, Cameron has surrounded himself with, the number increasing as he gets more insecure. By now even a public jaded with the cosy elitism of New Labour is beginning to notice that the old ruling class has simply taken over. So too are the middle-class members of the Tories who are now flocking to the UKIP, the process accelerated by the “Blue Boar” remarks.

Could events such as this eventually produce a split in the Tories? The party is one of the oldest and most united in the world. But parties are always coalitions, and they come under pressure when minor issues come to the centre of politics. Cameron, now looking like a rather hapless PR goon, may make the history books yet, if he can simultaneously put same-s-x marriage on the statute books and split the Tories straight down the middle.

Forget the popcorn. Bring on the Eton Mess.