A no-deal Brexit would be the deranged action of a rogue state

The Conservative party is in a post-Theresa May state of mind. The prime minister might cling to power for a while longer, tenacity being her most consistent quality, but the call to postpone a parliamentary vote on her Brexit deal feels like a condemned prisoner’s last-ditch plea for clemency. Moving the date doesn’t commute the sentence.

That means there could be a Conservative leadership contest within weeks, even days. May’s deal would then be history, and the race to succeed her will feature candidates who say that Britain can leave the EU with no deal at all. If that isn’t shocking, it proves that Brexit has deadened nerve endings that once reacted to high-voltage political insanity.

A no-deal Brexit guarantees severe pain for the country. It is not a normal item on the policy menu, yet the Tories conspire to make it banal. Boris Johnson writes that “we need to massively step up our preparations for leaving without an agreement”, claiming this will spur the EU to provide “a great deal”. That is a bluff within a bluff that was called long ago. Johnson cannot still believe that Brussels is intimidated by Britain threatening to impose an economic blockade on itself. Using readiness to do something deranged as a negotiating tactic is the behaviour of a rogue state. But Johnson has waded too deep into roguishness to go back, and others follow. Dominic Raab joins David Davis as a leadership contender who thinks he could get a better deal in Brussels, despite both having lived that dream once already as failed Brexit secretaries. Raab is on the record as believing that a collapse in negotiations would not be a disaster, because there might still be “no-deal deals” available.

Panting after Raab and Johnson in the dishonesty steeplechase is Jeremy Hunt. He once warned that a cliff-edge Brexit would be regretted for generations, but now positions himself as the candidate for a “managed no-deal” departure. That is like promising a managed car crash. It sort of makes sense to steer into a ditch if the alternative is steering into oncoming traffic – but why not just change lanes or stop the car?

There are working brakes. That was confirmed by the European court ruling that Britain’s article 50 notification can be unilaterally rescinded. So a pro-remain government could easily abort Brexit, but affirmation of the mechanism doesn’t bring such a government into being. It is often said that there is no majority in parliament for no deal and that MPs would not permit it, which is half true. The Commons could back a motion urging a prime minister not to take Britain over the cliff, but it would not have the force of law, nor would it stop EU membership expiring next March. A sufficiently unhinged occupant of No 10 could ignore the instruction and keep rolling towards the edge.

There is a notional coalition of sanity in the Commons to rally behind some non-calamitous way out of the crisis, but there is no simple constitutional way for that group to impose its will. They are divided between supporters of a super-soft Brexit, along Norwegian lines, and supporters of a second referendum. The would-be Norwegians fear that another referendum would be lost to a campaign of such wild, caustic nationalism. The full remainers respond that Norway-plus options are incoherent, retaining all the flaws of Brexit without appeasing leave voters’ rage. A cross-party alliance is also hindered by Labour’s insistence that a magic, painless Brexit becomes available if Jeremy Corbyn is prime minister. It doesn’t.

Besides, Corbyn in No 10 doesn’t fit any Tory MP’s definition of a non-calamitous outcome. That doesn’t mean Conservative moderates are ready to indulge May for much longer. They have written her and her deal off. Yet some also itched to vote for it as a gesture of defiance to hardline leavers. Remainers in the cabinet want a definitive Commons showdown on the deal sooner rather than later, so they can say they have done their utmost in government to deliver the referendum mandate – that their debts to June 2016 are paid. They are then free to call for alternatives that cross May’s strangulating red lines. Postponing the “meaningful vote” binds ministers into an ongoing pretence of loyalty that they will struggle to maintain.

And as May’s moribund deal blips on life support in the Commons, no deal is still the default setting. Most MPs, businesses, diplomats and democratic leaders worldwide (with the possible exception of Donald Trump) recognise that would be a catastrophe: abolishing, overnight, the legal basis on which the UK’s trade relations are built; ripping up the most sophisticated alliance with continental Europe in British history. It cannot be done without triggering a cascade of civil emergencies. But pro-Brexit ministers have preferred not to let sharp facts pierce their ideological bubble. Civil servants have written gloomy memos not expecting their advice to be taken but in anticipation of the inquiry that will one day be held; so there will be a record of the warnings that were ignored.

It is bizarre enough that a powerful faction in the ruling party of a once-serious country should embrace a doctrine of gratuitous national self-harm. It is more disturbing still that the same deluded cult might soon get a shot at capturing Downing Street. Moderate Tory MPs say they will thwart a no-dealer in a leadership contest, but that is an ambition, not a guarantee. They will struggle to convince Tory members that no-deal scenarios are beyond the pale, not least because May has routinely preached the opposite. It is the incumbent prime minister who told the country that “no deal is better than a bad deal”. She kept the slogan going long after she stopped believing it, if she ever did.

Now, with MPs of all stripes queuing up to call her deal a bad one, hard Brexit ultras invoke May’s own mantra as the guide to what should happen next. The prime minister enabled the delusion. She legitimised and sanitised one of the most poisonous ideas in British politics. She was complicit in writing “no deal” on the menu of sensible Brexit choices and now she has no authority left to erase it. She told the fanatics what they wanted to hear. She gave them their best line, loading the rhetorical gun they now use against her. On a human level this predicament might stir pity, but as a dereliction of a duty to the country, the irresponsibility is unforgivable. Anyone who still takes seriously the idea of no-deal Brexit, who pretends it is a reputable option, should be disqualified from holding the job of prime minister. It is a test Theresa May has already failed.

• Rafael Behr is a Guardian columnist