Brexit expresses a part of what it means to be British, albeit not the part anyone who campaigned for it had in mind. It is the national tendency to find satisfaction in being dissatisfied. It is the spirit of picnics in the rain and self-congratulation for having stuck with a plan long after it stopped making sense.

It looks increasingly plausible that Theresa May will complete a deal that pleases no one and is approved by parliament anyway. The outline is coming into focus. To keep the Irish border friction-free, the UK will be locked into maximal regulatory alignment with Brussels. There will be some dodgy escape clause, sold to Tory Eurosceptics as a future portal to the mythical global trade utopia of Canada-plus.

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That model would be too soft for the hard nuts and too hard for the softies. It would launch the UK into an outer-European orbit without a seat at mission control. It would be worse than EU membership, but less wantonly self-destructive than breaking off the talks and running at next March’s cliff edge. Some Tory cliff-jumpers (with their own private financial parachutes) will reject any deal. Their number is uncertain but probably enough for Downing Street to need votes from Labour MPs who like neither Brexit nor May. Why should they, or the pro-European Tories who agree with them, bail the prime minister out? The answer is fear – of no-deal chaos and of constituents who just want out; no quibbling over terms and conditions.

The sole merit in May’s model will be its availability. It will be an Angus Steakhouse of Brexits – the uninspiring place you end up in because it’s there, and you’re hungry and tired of walking in circles looking for an elusive destination to satisfy everyone in your party. The alternative is to hold out for something better at the risk of getting something worse. Here the pro-European camp splits. On one side are those who say the only way to avoid the pointless cost of Brexit is by calling it off, which requires another referendum. On the other side are those who see the social impact of a referendum as costlier than the economic hit of an orderly Brexit. They flinch at the thought of a campaign that, judging by recent precedent, would be neither civil, nor decisive.

This debate among former remainers is now the most important battle in British politics, and it transcends traditional party allegiance. It centres not on whether leaving the EU is a good idea but on whether it has to be done anyway, in diluted form, as the fare for moving the nation on. The dilemma: gamble on a people’s vote, reigniting a horrible culture war with no guarantee of victory, or concede defeat with the consolation prize of a customs union.

Another referendum is a tough sell when people can still taste the bitterness of the last one. Yes, there is a difference between a leap in the dark and informed consent based on a concrete proposal. The 2016 poll was held in a fog of ignorance and misinformation. Allegations of fraud in the financing of the pro-Brexit machine are reason enough for some to demand a rematch. But the reluctant Brexiters worry that remain arguments still sound condescending to many leavers’ ears. The remain message is vulnerable to caricature as a sneer that stupid racists got the question wrong and must resit the exam until they give the right answer.

Millions of voters saw Brexit as a once-per-generation demand for change, unique and irreversible. If MPs are thinking of reversing it, they’d better have a bloody good sense of what they are offering instead. Anything that looks like restoration of a Westminster ancien régime could stoke a rage to shake the foundations of British democracy.

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But a backlash is not averted by going through with Brexit. There is no chance of May’s deal meeting every (or any) advertised benefit of quitting the EU, so those who missold the adventure will start parcelling out blame, directing none at themselves. Remainers might fear reopening painful divisions, but Brexiteers have shown no interest in national healing. Theirs is the Trumpesque politics of salting wounds and scoring the howls of pain into nationalist marching songs.

Boris Johnson, Jacob Rees-Mogg, Nigel Farage, Arron Banks – these are cowards who flee responsibility for decisions they urge on others. They long ago renounced ownership of any practical Brexit outcome. It was never their intention to preside over the enactment of their mendacious campaigns and it is not their intention to lay down arms once the UK is out of the EU. They look forward to the day when May’s model has failed so they can steer the ensuing grievance towards scapegoats closer to home than Brussels.

Here, then, are some questions for pro-Europeans who do not want to face the Brexit conmen in another referendum: do you really think Johnson-Faragism is an unbeatable proposition or will you dare to take it on? When? If you surrender the trench of EU membership, where do you retreat to fight again? If you let Brexit pass because you were afraid to argue from principle that it is a mistake, what will your argument be when the mistake is found out?

The temptation to settle for anything the prime minister brings home will be great. The lure of a return to politics that isn’t about Europe is strong. It is also a mirage. Hard leavers will hate May’s deal, but they will be relaxed if former remainers want to pull the trigger that kills EU membership. Those suckers will own the terms of Brexit without ever having believed in the goal. Then the people who should most take responsibility for the mess that follows will laugh as they heap blame on the MPs who thought it was a bad idea and, for reasons history will struggle to admire, did it anyway.

•Rafael Behr is a Guardian columnist