In the face of a crushing, historic defeat of her Brexit deal, May has few options left.

Despite the loss and tomorrow’s no confidence vote, Article 50’s two year deadline means the UK will leave the EU on 29th March, deal or no deal, unless Westminster finds another route. Damaging uncertainty continues.

READ MORE: Theresa May's Brexit deal suffers crushing Commons defeat

Let’s be clear what lies behind this defeat. The most extreme Brexiters opposed a deal that would have given them what they want – the UK leaving the EU. And the DUP opposed the deal over a backstop that has widespread support in Northern Ireland.

Meanwhile, under Jeremy Corbyn, Labour also helped to defeat this Brexit deal, despite its own splits and fudged position. Yet the withdrawal agreement and political declaration allow for the very thing, a customs union, that is the only clear element of Labour’s Brexit policy.

Ironies abound. Corbyn is happy to call a no confidence vote, but refuses to oppose Brexit. Meanwhile, Brexiters voted against a Brexit deal because they clearly have no confidence in their own arguments that technology can solve border problems – whether in the Irish Sea, at the Irish border or UK ports. They fear the customs union that the backstop entails, as they rightly see that they cannot provide a way out of it.

READ MORE: SNP ramp up calls for People's Vote after May defeat 

The UK is in an acute political and constitutional crisis – with continuing major economic impacts. One particularly encouraging part of tonight’s vote is the cross-party working that has drawn in remainer Tories, remainer Labour, SNP, LibDems and Green MPs to search for a way both to halt Brexit and to stop a no deal Brexit.

Can Westminster take control of Brexit from a divided, ineffective government? It’s the crucial question in the coming hours and days. There may yet be a general election even if many think the no confidence vote will not pass. Or perhaps a cross-party unity government will form to look for a compromise either through a People’s Vote or a so-called ‘soft’ Brexit (‘soft’ always meaning alignment with the EU with no say, no vote, and no seat at the table).

Or May could yet stagger on. But the EU having seen the depth of May’s defeat may stand well back, waiting for the UK to come to it with a plausible way ahead. Meanwhile, European Council president Donald Tusk’s immediate response suggests he’s backing the UK staying in the EU.

In this political crisis, will May still steer the UK to Brexit? Will Corbyn step in and in what direction – on a compromise deal with May (extraordinary but not impossible) or towards a further referendum, if he fails to get a general election? Or will a cross-party group seize the reins looking to keep the UK in the EU? The Brexit crisis just got much deeper. Government, opposition or the Commons itself – who, if anyone, will now take control?

Kirsty Hughes is the director of the Scottish Centre on European Relations