What has the government actually got from the European Union? That’s the question that will define the next 24 hours.

David Lidington, Theresa May’s de facto deputy, told MPs on Monday that the government had secured “legally binding changes” to the withdrawal agreement.

The main – but crucially not the only – bone of contention between the government and backbenchers, both within the Conservative Party and the DUP, is the backstop, the provision designed to prevent a hard border on the island of Ireland regardless of what happens between the EU and the UK. It does that by keeping the whole of the United Kingdom within the customs and regulatory orbit of the EU.

But the two parties have slightly different concerns. The concern that committed Brexiteers have on the Tory backbenches is that the whole of the United Kingdom will be trapped within the backstop indefinitely, forced to follow EU regulations on goods and customs forever while having no say in them. The fear that the DUP have is that England, Scotland and Wales will be able to escape the backstop but that Northern Ireland will remain within it, erecting permanent and enduring barriers between Northern Ireland and the rest of the UK.

Has the government secured meaningful concessions on that issue? The answer, handily, is the same as to whether or not the government has secured a genuine cash bounty for leave-supporting towns, or enduring protections for workers’ rights: a big, fat, no.

The big problem as far as the backstop goes is that while Conservative backbenchers want guarantees that they can escape whenever they so wish, what Ireland – which, unlike the United Kingdom, is staying within the EU – wants is a guarantee that, come what may, there will not be a hard border on the island of Ireland.

As I said yesterday, there is no way to give the British Conservatives what they want without undermining the entire case for staying in the EU.

Instead, what has happened is that the government has secured further undertakings that the European Union also dislikes the backstop and doesn’t want it to become the default.

Will it move the dial as far as tomorrow’s votes on Brexit are concerned? Well, as with those concessions on workers’ rights and money are concerned, it depends on the known unknown of tonight’s Brexit vote: just how big the group of MPs, on the Conservative and Labour benches, that desperately wants to find an excuse to vote for the deal. May has managed to lowball to the point where only the most desperate are going to vote for the deal today.

The big question is: is that coalition of the willing large enough to keep May’s deal in contention over the coming weeks, when MPs seek to lay out a new path out of the Brexit crisis?