One of the more boring truths about the Brexit process is that there is no majority to stop it. The Labour leadership has neither the desire nor the inclination to whip in favour of it and if they did they wouldn’t be able to scare up enough votes to pass it without the support of at least 32 Conservative MPs. Many of the perennial Conservative rebels – Nicky Morgan, Jonathan Djangoly and Nick Boles among them – have publicly ruled out ever facilitating another referendum.

But any other Brexit outcome also has significant problems. There is not, as it stands, a parliamentary majority for the Brexit deal negotiated by Theresa May. So what about a softer Brexit, like the Norway Plus model proposed by the cross-party alliance of Boles, Stephen Kinnock, Nicholas Soames, Lucy Powell and others?

That has several advantages that a second referendum does not, not least that it has more support among the Labour leadership and has fewer committed opponents on the Labour backbenches. Although in practice, the ability to restrict the free movement of people when you are in the European Economic Area is nugatory, it gives Labour MPs in constituencies where there is considerable opposition to the free movement of people something they can say is being done. While it is not certain that membership of the EEA can command a majority in Parliament, it is less politically fraught for nervous Labour MPs than seeking another referendum.

But there is another bloc of reliable pro-European votes in Parliament who have major doubts about a Norway Plus Brexit which complicates the hopes of a Norway Plus Brexit too: the SNP.

It’s not quite fair, as one critical SNP MP once said to me, that the party has “worked backwards” from Nicola Sturgeon’s personal sense of horror at the referendum result, but it is true to say that the prediction at the top of the SNP that dislike of Brexit would trigger a mass rethinking of attitudes towards the Union hasn’t quite worked out as they hoped. Brexit has made a chunk of people who voted to stay in the United Kingdom and the European Union rethink their feelings about Scottish independence, but it is also made a chunk of people who voted to leave the United Kingdom and the European Union go in the opposite direction. The result is that the polls at the moment show a similar result to that in the 2014 referendum.

While that led to the SNP losing both seats and votes in 2017 election, they have rebounded in the polls since as attitudes on Brexit harden across the United Kingdom. Their position on Brexit has hardened too, from flirting with Brexit into the EEA to calling for not one, but two, fresh referendums: one on the Brexit result of 2016. and one on the No vote of 2014.

This is partly about the policy challenge of independence, and partly about the politics of securing it. As SNP MPs will privately concede, the economic trade-offs of independence become much, much harder if England and Wales are outside the single market of the European Union. There’s a weird paradox in that an economically destabilising Brexit is good for the emotional case for getting away from a rogue England, but bad for the policy case about how difficult that escape would be.

It’s also bluntly true that staying in the single market and customs union while not having the ability to shape the rules is largely undesirable – there are positive arguments for doing either, but the only case for doing both is that it is a non-disruptive Brexit outcome that might pass the House of Commons.

That’s why it doesn’t make sense for the SNP to support the idea of Norway Plus from a policy perspective. While they might aim for Norway-style membership of the EEA (it has a lot to recommend it to Scotland, as they would be out of the common fisheries and agricultural policies, but inside the single market), there is little to recommend that an independent Scotland stays in the customs union.

And from a political perspective, voting for any Brexit outcome robs the party of the ability to argue that Scotland has been taken out of the European Union “against its will”. That means that any parliamentary majority for Norway Plus has to find 35 votes from somewhere else.

It comes back to the central problem of Brexit – that there is no outcome to the crisis that doesn’t rely on someone deciding to take political damage to prevent a no deal Brexit. And the threat of no deal Brexit is sufficiently troubling that no side believes they will be the one that has to.