Both camps in the Tory parliamentary party are focused on one number: 152. That’s a majority of Tory MPs. David Cameron desperately wants to get over that hurdle.

Some in the antis’ camp think the PM will easily do that because of the arm-twisting going on behind the scenes. Others amongst the antis say “Cameron’s still struggling.”

One Tory MP voting against the bill said “if I hear one more person call this a ‘free vote’ I’m going to hit them. People are being told their careers are over if they go against the prime minister on this.”

And there are signs of seepage in the anti camp. Daniel Kawczynski, for one, is now backing the bill, I hear.

5 gaymarriage r w Gay marriage: Tories split down the middle?

Another Tory MP who’s seen some of the speeches to be delivered this afternoon says Tories will be “ripping bits” out of each other. I also hear that some Tory MPs are determined there shouldn’t just be two votes – the second reading and the procedural motion – but potentially five, including a money resolution and votes on deferred divisions.

It is, this particular MP says, a sign of how furious some Tories are and how determined they are to make life difficult for the top table. Votes later in the progress of the bill, on rebel/spoiler amendments, would be whipped so the trouble is not over even when David Cameron wins the vote (with the vast majority of Labour and Lib Dem MPs’ backing) tonight.

Senior Tory Cabinet members did some lobbying this morning with a letter to the Telegraph. The leadership hopes that IDS and Chris Grayling backing gay marriage will give cover to some potential “rebels” coming back to the leaders. Maria Miller, the culture secretary, is about to address an open meeting of Tory backbenchers.

But it’s very striking that David Cameron has not been leading from the front in the last 48 hours. He pulled out of public backing for the bill he had considered giving on Monday, and has similarly (and unusually) not been doing personal persuasion sessions with MPs to beef up the vote. This, his opponents say, is because it would be counter-productive and the whips have told him so. Not a good sign when you think the usual powers of patronage and loyalty are bust and better off not deployed.

Now, should this “worry” David Cameron in terms of political fallout? The latest YouGov poll suggests: a 15 per cent gap opening up between Labour and the Tories, and in numbers just put up on the YouGov website you can see how it might be the “divided party” image that is driving this. A new high of 71 per cent of all voters think the Tory party is divided (and that includes 57 per cent of Tory supporters – they should know). You can compare it with past questions by clicking here.

You can read much here on why you shouldn’t take campaigners’ polls claiming gay marriage will lose the Tories the election at face value. And you can get a good idea here of the sort of thinking that informs David Cameron’s push for gay marriage. Lord Ashcroft, David Cameron’s former party treasurer and marginals campaign supremo, writes:

“… Joiners (who did not vote Conservative in 2010 but would do so now) and Considerers (who did not and would not tomorrow, but would consider doing so in the future) were more likely to favour gay marriage than the population as a whole, and more likely to say they felt strongly about it. 15 per cent of Joiners said they were in favour of the idea and would be more likely to vote for a party that allowed it - half as many again as among voters generally, and three times as many among as Loyalists and Defectors.”

I hear the rebels in their late morning meeting estimated they had 140 Tory MPs voting against the gay marriage bill. They were particularly pleased to see the two law officers withholding support from the PM – Dominic Grieve, the attorney general is expected to abstain, and Solicitor General Oliver Heald is expected to vote against.

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