Its official: the withdrawal agreement is not going to pass parliament. Theresa Mays last hope was that the revised political declaration – the rhetorical boilerplate about the future that accompanies the binding accord about the divorce deal – would win enough Conservative MPs round to, at the least, bring the number of rebels down to a point where Labour MPs worried about no deal might consider voting for the deal again.

But it swiftly became clear that, on that metric, the revised declaration is a failure from beginning to end. The withdrawal agreement is repellent to Brexiteer ultras on both sides of the house, and is losing votes among pro-European Tories who favour another referendum into the bargain.

As for Labour, the demands of both their own electoral coalition in the country and the party membership means that, regardless of content, Jeremy Corbyn will instruct his MPs to vote against, with the Oppositions six tests – a combination of some of David Davis wilder promises on the campaign trail and the preoccupations of Labour MPs – designed to be failed.

So what happens next?

Theresa May deposed

I cannot envisage a situation in which losing the vote triggers a vote of confidence in Theresa Mays leadership, for two reasons:

1) I am yet to speak to a Conservative MP who is currently opposed to removing Theresa May as leader, but would change their mind if she lost the withdrawal agreement vote; which links into

2) anyone with a calculator and half a brain now knows that Mays vote is not going to pass.

No one is making political calculations based on the idea that the deal might actually pass first time around, including MPs on the fence about getting rid of the Prime Minister. In any case, regardless of who is in Downing Street, the essential political dilemma remains unchanged – though the length of a leadership election would surely increase the chances of a no deal exit by mistake.

An early election

Labour will, of course, once the withdrawal agreement has been defeated, put down a motion of no confidence in the hope of triggering an early election. I cant see how, at the moment, this has a chance of passing: it would require Conservative MPs to be willing to vote for an election which has a high chance of turning into a wall-to-wall disaster.

It comes back to the question that one minister put to me recently: “What would our Brexit policy be?” It couldnt be the withdrawal agreement, as if that could unify the Conservative Party they wouldnt be at risk of having an election; so you would rapidly have almost as many Brexit positions as there are Conservative MPs. Instead of fighting the campaign they hope to next time, in which Jeremy Corbyn faces the scrutiny of a would-be Prime Minister, the campaigns theatre would probably be dominated by blue-on-blue infighting.

It may be that the stand-off between the Conservative government and the DUP over the backstop does eventually get to a point where the DUP decide they are better off pulling the plug on the government and voting for a no confidence motion. But we arent there yet, and I dont see how we will get there by December, when the withdrawal agreement comes before the House of Commons.

Brexit stopped

Short answer: Lol, no chance.

Longer answer: we arent even in a political situation where a large number of MPs feel able to make an uncaveated argument in favour of the free movement of people, an essential rule of single market membership and of staying within the bloc, let alone one in which a majority of MPs votes to bin off the referendum result entirely. And thats before you remember that it is still not clear if the ability to call off the Article 50 rests solely in the United Kingdoms hands.

Withdrawal agreement rewritten

Short answer: not in a billion years.

Long answer: the withdrawal agreement has to be acceptable to the Irish government – and whoever is in power in Dublin will never be able to survive the political fallout of signing an accord that puts a border on the island of Ireland, which is why it has the backstop, which is what is causing so many internal Conservative problems.

Although the future declaration might be radically different under a Labour government, whether a minority or majority one, the withdrawal agreement, which concerns questions arising from divorce, would not look that different regardless of who is writing it.

Theresa May might rewrite the political declaration to attract Labour votes, but thats about it.

Second referendum

Now this, Im less sure of. As it stands, the Labour partys official policy is essentially to try everything else short of another referendum and then, in extremis, to go for that. I am dubious about two parts of this: firstly, I am sceptical that Jeremy Corbyn would ever want to get to this position outside of an election or coalition negotiation. In order to get Labour through an election campaign or into government supported by the smaller parties of the left, sure. But imperil Brexit and potentially prop up a Conservative government? I cant see it.

But even if Corbyn were to decide to back another referendum, there is no button in the Labour leaders office to compel every Labour MP to vote for the deal. Dont forget that 25 Labour MPs have broken the whip to harden Brexit, including the seven committed Brexiteers – so we are realistically talking about a situation where two highly unlikely things happen:

1) Jeremy Corbyn decides to risk his own electoral coalition in support of a cause that is not his own, and

2) around 30 Conservative MPs decide to vote with him.

Im not saying these two things definitely cant happen, but they are both individually pretty unlikely, let alone together.

Deal passes eventually

I first mooted this as the “Tarp scenario” back on 11 July. Back in 2008, George W Bushs programme of bailout measures failed to pass the House of Representatives on the first time of asking, and the result was both political damage to his Republican party and economic damage to the United States, before it passed with further concessions to the opposition Democrats.

Since then the analogy has taken on something of a life of its own and its meaning seems to have narrowed somewhat – now it implies the deal will pass on the second time of asking after stock market panic.

Market panic looks very unlikely to me, for the same reason that a new attempt to remove Theresa May after the deal fails looks unlikely: everyone expects the withdrawal agreement to fail. But everyone also expects the deal to pass second time around, which it may not.

But it feels to me quite likely that eventually, if pro-European MPs cannot get another referendum, if Labour cannot get an early election, if the withdrawal agreement remains unchanged, if there is not political appetite to stop Brexit, eventually, parliament ends up voting for the withdrawal agreement – but who knows how much economic turbulence the United Kingdom will go through and how much political damage the Tory party may have to suffer to get to that point. I still think this is the most likely outcome though the next most likely outcome is…

No deal

Its very easy to say “Parliament doesnt want no deal” or “No government would ever let no deal happen”. The problem is that a no-deal exit is the default scenario. Its what happens if no one blinks, or if everyone just assumes that “something” will prevent no deal. Given all the other scenarios require someone to give up their political project, risk electoral damage or potentially split their party, and everyone essentially assumes that someone else will decide that they are prepared to give up their political project, suffer electoral damage or split their party, we should be much more alive to the possibility that, despite everything, a no deal exit might actually happen.

Stephen Bush is special correspondent at the New Statesman, the EI Political Commentator of the Year, and the PSA's Journalist of the Year. His daily briefing, Morning Call, provides a quick and essential guide to domestic and global politics.