If a no-deal Brexit happens, it will be because Leavers just want it more. Or because the various opponents of no deal won’t put country ahead of party. Those interconnected analyses are popular among pro-European activists and are a recurrent theme on Lewis Goodall’s Sky Views blog.

It’s a superficially attractive view – which is why the various political parties that are opposed to no deal use it against each other rather than debunking it – but it is highly flawed. Why?

Well, that starts with another set of questions: Why haven’t we left the European Union yet? Why was a no-deal Brexit averted in March 2019?

The answer is: because in the 2017 election the Labour Party and the Liberal Democrats gained seats at the Conservatives’ expense.

Wipe out the five direct Liberal Democrat gains from the Conservatives, let alone the 28 seats that Labour won from the Tories, and you have a House of Commons with either a majority for a negotiated Brexit, likely with a customs and regulatory border down the Irish Sea, or for a no-deal Brexit.

“Doing whatever it takes to stop a no-deal Brexit” or indeed “doing whatever it takes to stop Brexit” cannot be seen as a separate political project to “acting in the best electoral interests of the Labour Party and/or the Liberal Democrats”, at least not in England and Wales.

Let’s take stopping no-deal, though an identical dynamic. The challenge that the various opponents of no-deal have to manage is that they not only need to stop no-deal Brexit on 31 October – they need to find a way of doing so that means they can stop it the day after too. If the way that no deal is stopped paves the way for an election in which Labour and the Liberal Democrats lose seats in England and Wales then no-deal has not been “stopped” – it has simply been delayed, because the result of that election would be a parliament with fewer opponents of no deal in it.

The Labour leadership believe, rightly or wrongly, that ceding the idea that an alternative government could be led by anyone other than Jeremy Corbyn would doom their political project. The Liberal Democrats believe, rightly or wrongly, that making Jeremy Corbyn pime minister, even on a temporary basis, will mean they lose rather than gain seats from the Conservative Party.

Either or both of these assumptions may be wrong. But the fundamental truth is that neither party can simply focus entirely on what happens on 31 October – they need to also be able to maintain and defend their victory on 1 November, and 1 December for that matter. Whereas once a no-deal Brexit, or any Brexit, has happened, we are out – not necessarily forever, but certainly for a while.

And that’s the biggest difference between those MPs who want no-deal and those who want to oppose it: not that one side wants it more or less, but that their political incentives and challenges are different.