Chris Mason: Crunch day for the Rwanda asylum bill

Another day, another debate - on Rwanda.

When 60 of your own MPs vote against you, as they did last night, it is a hefty assault on any prime minister's authority.

Throw in a trio of Rishi Sunak's colleagues willing to resign in order to do so and the depth and breadth of frustration, anger, even contempt from some Tories about the government's Rwanda plan is there for all to see.

The numbers "speak for themselves", one leading rebel told me. Well - up to a point. It doesn't mean the policy is finished.

On Wednesday, MPs will debate what are dubbed the pyjama injunctions of the European Court of Human Rights - last-minute, often late night, demands from the Strasbourg court to haul migrants off a plane.

Rewind to June 2022, when Boris Johnson was prime minister, and it was these Rule 39 injunctions, as they are formally known, which hauled several migrants off a plane that was just about to set off for east Africa.

Rebels want the default position to be that these injunctions are not binding.

Ministers will attempt to smother discontent by arguing this amendment isn't necessary by promising, I hear, to amend the Civil Service Code and Home Office guidelines to spell out a presumption these injunctions can be ignored.

In other words, the message to Tory MPs will be, you don't need to back this amendment, because we have a plan that will have the same effect anyway.

Let's see how many of them buy that.

But the big moment will come later, assuming no amendments are passed, when MPs get the chance to vote on the government's Rwanda plan in its entirety.

How many of those 60 rebels are actually willing to vote the whole thing down?

If they did, they would kill the government's policy outright, and inflict a colossal reputational hit on the prime minister, in the year of a general election.

So far, very few Conservative MPs have explicitly committed to voting against the bill at what is known as Third Reading, expected on Wednesday night.

I detect a quiet confidence among ministers that, despite what we saw on Tuesday, when MPs do vote at Third Reading, the government can win.

Moods can move, and nothing is being left to chance. Every Conservative MP's view is being accounted for.

And there is an awareness that for every MP who wakes up on Wednesday morning with a rebellion hangover, a queasiness at having defied the prime minister, some might find they like the taste of rebelling.

And so, boy, there is plenty of persuading, reassuring and phone calling to do.

And - even if the government does win - the policy then heads to the House of Lords, where it can expect to bump into more opposition.