Theresa May has become the first British Prime Minister for 41 years to lose a vote on a finance bill after 20 Conservative MPs rebelled against the party whip and backed Yvette Cooper’s amendment, which sharply limits the government’s tax-raising powers in the event of a no-deal Brexit. What does it mean for the resolution of the Brexit crisis?



Although Cooper’s amendment was billed as “preventing no deal”, as she herself freely conceded in the House, the amendment itself does no such thing. In fact, by limiting the government’s powers to raise revenue, it sharpens the rocks at the bottom of the ravine rather than pulls the country away from the cliff edge. But the amendment has two important implications. The first is that it gives Parliament an opportunity to avert a no-deal exit at the eleventh hour if the need arises. The second is that, as it was billed and seen by MPs as an opportunity to demonstrate the strength of the parliamentary majority against a no-deal exit it gives us a sense of the size of that majority – and its limitations.



First, to the size. It’s a small majority: just seven votes, with 303 votes in favour of Cooper’s amendment, and 296 against. But we can fairly say that it would be a little bit bigger in a hypothetical “no deal versus x” vote (x being “whatever the alternative to no deal is”), for several reasons. The first is that ultimately this vote is not going to prevent a no-deal exit, and there is not the immediate risk of one, which means that we should regard 20 as the lower end of the potential Conservative rebellion. We can add at least six votes from MPs currently in ministerial offices, as several MPs would resign from the government rather than allow a no-deal exit to occur. (The total number of possible resignations is bigger than six, but it’s a universal truth that not everyone resigns when pushed.) We can also fairly add a handful of extra votes from the backbenches of MPs in marginal constituencies who do not have religion on the European issue and wouldn’t, when push comes to shove, risk a no-deal exit.



But it isn’t enough for Parliament to vote against a no-deal exit – it has to vote for something to have in its place, whether that is another referendum, an early election, the withdrawal agreement as currently written or the withdrawal agreement following revisions to the political declaration, or simply to revoke Article 50 without a referendum. Can those 303 votes be marshalled in favour of any of those options?



Well, it certainly isn’t a majority for another referendum, let alone revocation without one. Cooper’s amendment only passed thanks to the support not only of the Labour frontbench, but also because of the seven pro-Brexit Labour MPs, only three voted against, with the rest of them either voting for Cooper’s amendment or abstaining. Stephen Lloyd, elected as a Liberal Democrat but currently sitting as an independent, has pledged his constituents that he will vote for Brexit but voted for Cooper’s amendment.



On the Conservative side, Nick Boles, Nicky Morgan and Jonathan Djangoly have all publicly opposed a second vote.



Take away those votes, and before you have even factored Labour’s EEA rebels – Labour MPs who backed a Remain vote in 2016 but refused even to abstain on a vote to take the United Kingdom into the EEA – and the majority on Cooper’s amendment has disappeared. (And don’t forget that Remainers need not only an enduring majority to pass a referendum bill but one big enough to resist amendments that would add a turnout threshold or other measures that could act as a poison pill to any referendum re-run.)



But the bad news is that a Norway Plus Brexit – the proposal put forward by Nick Boles, Stephen Kinnock and others whereby Parliament would amend the political declaration to signal the UK’s intent to join the European Economic Area and then pass the withdrawal agreement unchanged – wouldn’t, on these numbers, be able to pass either.



Why? Because if you take away the votes of supporters of a second referendum who have declared their opposition to an EEA Brexit – Mary Creagh, Chris Bryant, Wes Streeting, Peter Kyle, Mike Gapes from Labour, Sam Gyimah from the Conservative Party – then, once again, the majority for Cooper’s amendment vanishes. And that’s before you take away the 11 Liberal Democrat MPs, who have pledged to seek an “exit from Brexit” via a public vote, too. There are significantly more votes from within the Conservative Party for this flavour of exit than a second referendum but there may not be enough without at least some of the vocal pro-European critics of an EEA Brexit having to eat their words.



(It’s worth noting that most MPs backing a second vote have behaved more carefully as far as the EEA option is concerned, but that doesn’t matter in this case because the MPs who have come out in opposition to it are numerous enough to imperil an EEA Brexit.)



As for the withdrawal agreement, we know that has no chance of passing the House of Commons. Now, of course, one can reasonably argue that when given a choice between the cliff-edge and any of those options, most MPs will fall into line behind any option. But that hasn’t happened yet and not enough MPs on any of the three sides seeking an alternative to a no-deal Brexit – not supporters of May’s deal, not advocates for an EEA Brexit, and not the People’s Vote campaign – have yet shown any willingness to sacrifice their political objectives to prevent a no-deal Brexit.