The situation has been fluid all day in Westminster, but The Guardian’s calculations suggest Boris Johnson just might get his Brexit deal passed. Ten Labour MPs have declared their intention to support the proposal, along with enough Tory rebels returning to get to a majority of two, even without the DUP. That’s an early assumption, however, and a key loss on a procedural motion might throw a spanner into the works for Johnson tomorrow.

For now, though, Johnson looks like he’s building a winning coalition:

And now there were 10: @OnnMel is backing Boris' deal. By our numbers, Boris Johnson has a majority of *two* for his deal tomorrow https://t.co/2DBWj354Bc

— Sebastian Payne (@SebastianEPayne) October 18, 2019

Onn partnered up with Tory MP Victoria Prentis on an op-ed to urge unity in getting Brexit done and “move on”:

Last month, we came together with colleagues across the house to find a middle ground between the extremes of no deal and a second referendum. Our mission was to give a voice to the silent majority – both in parliament and across the country – a voice to those who respect the result of the referendum, and who want us to leave with a deal and move on. …

That’s why we have decided to write together the day before this historic sitting – not just as a proof that MPs of different stripes can work together, but to implore our colleagues to use this unique chance to help us move on, and get back to helping our constituents.

A no-deal Brexit will risk their prosperity, and a second referendum will only deepen the schism of the past three years. Pride needs to be swallowed on both sides, and clear heads must prevail.

The risk of letting this final shot at a deal slip through our fingers is too great. Our collective hope rests on brave Labour MPs, and indeed others, who can see that.

There isn’t a word in this essay that supports any of the elements of the deal, nor a single word about Boris Johnson. Still, it appears that the momentum has swung his way and that Johnson’s deal might still pass.

That might not be the end of it, however. Some apparently suspected that Johnson might try to use this version of a deal as a stalking-horse for a later no-deal Brexit. Johnson’s government lost a vote to keep the authorizing bill from being amended, and Parliament began attaching conditions to the deal. The most significant of this is one offered by MP Oliver Letwin that suspends approval of the deal until the government passes enabling legislation, which is separate from the approval that may pass tomorrow:

The amendment would withhold approval of the deal, until the legislation to enact it was safely passed – a move that would automatically trigger the “Benn Act” and force the prime minister to request a further postponement of Brexit until 31 January. …

Sir Oliver’s amendment is a cunningly-crafted proposition which, crucially, could be voted for by MPs who want a deal, but don’t trust this one, and don’t trust the government.

It rests on the idea that were Parliament to approve the deal for the purposes of the Benn Act now, there might then be a danger that the subsequent legislation to enact it might be, somehow, derailed, resulting in a no-deal exit on 31 October.

With the Benn Act out of the way, they believe that some manoeuvre, some legislative judo move, by factions inside and outside the government, who favour a “clean Brexit” could leave no time for any effective counter… and Britain would be out, with no deal.

The perceived need to seek such a guarantee in legislation speaks to a profound lack of trust in Johnson and his fellow Brexit hardliners. Given all of the machinations on all sides over Brexit to this point, it’s hardly outside of the realm of possibility that Johnson could have been angling for a way to get to a no-deal Brexit by finding a way to get around the Benn Act. That would have been a clever ploy, one that would have enabled Johnson to avoid some of the political damage for splitting off Northern Ireland as he has in this current version of the deal while still claiming to have delivered a functional Brexit deal.

Letwin insists he’s not trying to scupper the deal but to save it:

“My aim is to ensure that Boris’s deal succeeds, but that we have an insurance policy which prevents the UK from crashing out on 31 October by mistake if something goes wrong during the passage of the implementing legislation,” Letwin said in an explanatory note sent to reporters.

It might, however, be a poison pill in the end that some Brexiters can’t swallow. At the very least, tomorrow’s sitting might end up being more academic than climactic:

Forcing the PM to ask for a delay even if MPs have voted for the deal certainly changes the dynamics around tomorrow

— Laura Kuenssberg (@bbclaurak) October 18, 2019

Biggest decision about tomorrow is what the govt decides to do if Letwin amendment passes. Do they pull the whole motion? Or proceed with it, knowing it no longer constitutes a meaningful vote?

— Lewis Goodall (@lewis_goodall) October 18, 2019

This assumes that the EU would grant another extension, a point that is far from established. However, it would be almost automatically granted if Parliament passed the authorization and needed a little more time for the enabling legislation to pass; certainly the EU would not jeopardize their own interests in a pedantic argument over the deadline with nothing else at stake. With that as the context and another no-deal escape hatch closed, will hardline Brexiters come along with Johnson? At least one of them announced this afternoon that she’ll throw in with the government on the deal:

After much consideration, I have decided to back @BorisJohnson deal. Obviously I would prefer No-Deal but I believe we are in real danger of losing Brexit with the Remain shenanigans and the stakes are dangerously high at the moment. My statement below. https://t.co/n9nEkJePRO pic.twitter.com/FHkJjNUtVW

— Andrea Jenkyns MP (@andreajenkyns) October 18, 2019

Johnson might still need a few more to get around the DUP, but it’s now leaning in his direction.