Healing bitter division is one of two great preoccupations haunting politics in the United Kingdom since the 2016 Brexit referendum — the second is hating Jeremy Corbyn.

On Wednesday, the Labour leader wrote a letter to the other main opposition parties proposing an alliance to block a No Deal Brexit, a prospect that has now become uncomfortably plausible with Boris Johnson as prime minister. Under the proposal, Corbyn would call a vote of no confidence in Johnson’s government; once the motion is carried he would step in to become a caretaker prime minister for a brief term. Corbyn’s powers would be limited; he couldn’t introduce new legislation. The sole purpose of his tenure as prime minister would be to negotiate a postponement of the Brexit deadline and call a general election. Labour would then campaign for a new EU referendum with a Remain option on the ballot.

The suggestion is calm, serious, and thoughtful. Most importantly, it includes a promise of a campaign for that second vote that so many centrists have loudly rallied for; the election everyone on the Left has longed for; and as mentioned, it severely limits Corbyn’s powers, but importantly, also blocks No Deal. It should bring everyone on board. Sensible parties were furtively positive: Plaid Cymru (the Welsh nationalist party) and the Scottish National Party said they were interested in discussing the idea when they appeared on the BBC Radio 4 Today programme.

But with this proposal, Corbyn has called the bluff of the extreme centrists and the obsessive Remainers. Since his scheme involves an election in which Labour would campaign for a second referendum, with Remain on the ballot, attacking Corbyn now means attacking the very ideas they claim to be fighting for. Sure enough, the Liberal Democrats shot the proposal down immediately, stating they would never countenance backing Jeremy Corbyn as prime minister, even if it meant stopping a No Deal Brexit — though leader Jo Swinson was perfectly happy to back David Cameron in the austerity cabinet of 2010. Meanwhile, centrist runaways in the Change UK/Independent Group for Change/Independent Group told journalists they, too, would not back a vote of no confidence against the government in order to stop a No Deal Brexit.

Thus, the hideous truth is now revealed, confirming what many on the Left have long been saying about the Liberal Democrats, the Independent Group, and a huge number of highly vocal centrist ultras on social media: for all their yelling that stopping Brexit is their sole concern, as long as stopping Brexit means Corbyn in a position of power — however minor and effectively powerless — they would prefer economic obliteration. Given the choice between Corbyn spending a few weeks merely acting out a pre-agreed script, on the one hand, and medicine and food shortages, a tanked pound, an economy in ruins, and widespread social panic, many centrists would choose the latter. Their hatred for Corbyn really does expand to fill so much of their mind as to incapacitate them.

There are several manias present in British politics today; Borismania has forced us into our current position. But the hatred of Corbyn and the obsession with stopping Brexit must now compete, and are all found in the same milieu: the middle-class person who sees themselves as a “thinking person” and “mildly green” but doesn’t know a huge amount about politics. That kind of person is anti-Corbyn and part of the Remain rally.

Make no mistake: these people would rather the Conservatives remain in power than a mild social democrat. They would prefer to see the country enter another, far harsher period of austerity, or see the economy shrink; after all, they weren’t touched by the first term of austerity, and they know the second will fall on the same people — the poorest. But they are overrepresented in the media and political class: people who consider themselves “a bit of a lefty” or left of center, who would prefer Boris Johnson to Jeremy Corbyn as prime minister, and who couldn’t see the problem with either the last Conservative government, the motions Corbyn voted against when Labour were in power, or the public spending cuts that made up the last austerity scheme. They constitute a small but vocal class of people who are angered because their perception of themselves as progressives has been undermined by younger people backing Labour now when they never did before. But rather than triggering inquiry into who these new politics activists are, all this does is elicit more hatred, abuse, and dismissal. Engage on Twitter and get accused of being a paid Russian troll, part of The Corbyn Cult, or simply a young idiot.

It might simply be annoying, but if this remains the attitude of the Greens and Lib Dems, it will usher in a No Deal Brexit that everyone agrees will have immediate effects on the poorest first. For the Lib Dems to claim their one purpose is to fight to stop Brexit, then dismiss the action that is most likely to stop No Deal Brexit, shows up the duplicitous reality: forced to choose between socialism or barbarism, despite their fluffy exterior and behaviour, they would choose barbarism.