O NE BY ONE , the principles on which the Brexit campaign was fought have been exposed as hollow. Before the referendum, Leavers argued that victory would enable them to negotiate a brilliant deal with the European Union. Now they advocate leaving with no deal at all. Before the vote they said that Brexit would allow Britain to strike more free-trade agreements. Now they say that trading on the bare-bones terms of the World Trade Organisation would be fine. Loudest of all they talked of taking back control and restoring sovereignty to Parliament. Yet on August 28th Boris Johnson, a leading Leaver who is now prime minister, announced that in the run-up to Brexit Parliament would be suspended altogether.

His utterly cynical ploy is designed to stop MP s steering the country off the reckless course he has set to leave the EU with or without a deal on October 31st (see article). His actions are technically legal, but they stretch the conventions of the constitution to their limits. Because he is too weak to carry Parliament in a vote, he means to silence it. In Britain’s representative democracy, that sets a dangerous precedent (see article).

But it is still not too late for MP s to thwart his plans—if they get organised. The sense of inevitability about no-deal, cultivated by the hardliners advising Mr Johnson, is bogus. The EU is against such an outcome; most Britons oppose it; Parliament has already voted against the idea. Those MP s determined to stop no-deal have been divided and unfocused. When they return to work next week after their uneasy summer recess, they will have a fleeting chance to avert this unwanted national calamity. Mr Johnson’s actions this week have made clear why they must seize it.

Of all her mistakes as prime minister, perhaps Theresa May’s gravest was to plant the idea that Britain might do well to leave the EU without any exit agreement. Her slogan that “no deal is better than a bad deal” was supposed to persuade the Europeans to make concessions. It didn’t—but it did persuade many British voters and MP s that if the EU offered less than perfect terms, Britain should walk away.

In fact the government’s own analysis suggests that no-deal would make the economy 9% smaller after 15 years than if Britain had remained. Mr Johnson says preparations for the immediate disruption are “colossal and extensive and fantastic”. Yet civil servants expect shortages of food, medicine and petrol, and a “meltdown” at ports. A growing number of voters seem to think that a few bumpy months and a lasting hit to incomes might be worth it to get the whole tedious business out of the way. This is the greatest myth of all. If Britain leaves with no deal it will face an even more urgent need to reach terms with the EU , which will demand the same concessions as before—and perhaps greater ones, given that Britain’s hand will be weaker.

Mr Johnson insists that his intention is to get a new, better agreement before October 31st, and that to do so he needs to threaten the EU with the credible prospect of no-deal. Despite the fact that Mrs May got nowhere with this tactic, many Tory MP s still see it as a good one. The EU wants a deal, after all. And whereas it became clear that Mrs May was bluffing about walking out, Mr Johnson might just be serious (the fanatics who do his thinking certainly are). Angela Merkel, Germany’s chancellor, said recently that Britain should come up with a plan in the next 30 days if it wants to replace the Irish backstop, the most contentious part of the withdrawal agreement. Many moderate Tories, even those who oppose no-deal, would like to give their new prime minister a chance to prove his mettle.

They are mistaken. First, the effect of the no-deal threat on Brussels continues to be overestimated in London. The EU ’s position—that it is open to plausible British suggestions—is the same as it has always been. The EU ’s priority is to keep the rules of its club intact, to avoid other members angling for special treatment. With or without the threat of no-deal, it will make no more than marginal changes to the existing agreement. Second, even if the EU were to drop the backstop altogether, the resulting deal might well be rejected by “Spartan” Tory Brexiteers, so intoxicated by the idea of leaving without a deal that they seem ready to vote against any agreement. And third, even if an all-new deal were offered by the EU and then passed by Parliament, ratifying it in Europe and passing the necessary laws in Britain would require an extension well beyond October 31st. Mr Johnson’s vow to leave on that date, “do or die”, makes it impossible to leave with any new deal. It also reveals that he is fundamentally unserious about negotiating one.

That is why Parliament must act now to take no-deal off the table, by passing a law requiring the prime minister to ask the EU for an extension. Even before Mr Johnson poleaxed Parliament, this was not going to be easy. The House of Commons’ agenda is controlled by Downing Street, which will allow no time for such a bill. MP s showed in the spring that they could take temporary control of the agenda, when they passed a law forcing Mrs May to request an extension beyond the first Brexit deadline of March 29th. This time there is no current legislation to act as a “hook” for an amendment mandating an extension, so the Speaker of the House would have to go against precedent by allowing MP s to attach a binding vote to an emergency debate. All that may be possible. But with Parliament suspended for almost five weeks there will be desperately little time.

So, if rebel MP s cannot pass a law, they must be ready to use their weapon of last resort: kicking Mr Johnson out of office with a vote of no confidence. He has a working majority of just one. The trouble is that attempts to find a caretaker prime minister, to request a Brexit extension before calling an election, have foundered on whether it should be Jeremy Corbyn, the far-left Labour leader whom most Tories despise, or a more neutral figure.