A run on the pound was once the kind of event that troubled a prime minister. If it was shown to be the direct result of a policy the prime minister refused to change, it might even have unseated them. No longer. Now a Conservative government’s central policy will not just crash the pound, but also end Britain’s manufacturing and agriculture overnight and block half the country’s transportation of food and medicines – and it shows no shame whatsoever.

Extraordinary and radical times demand a similar response. It may no longer be sufficient for parliament to tinker around the edges with Brexit. Because the no-deal trajectory is both real and unthinkable, politicians may finally decide it is time to challenge key orthodoxies. Brexit, in its current form, is not the will of the people – and it can be stopped. The outright revocation of article 50 is looking more likely, and more justified, than ever.

Revocation has, understandably, been considered Brexit’s nuclear button. Remainers in parliament have been unwilling to vote for it or even discuss it. But it may prove the only way to stop the catastrophe of no deal.

Revocation is the only option now because there is no time for a referendum before we crash out

If it is clear at the start of September that Boris Johnson won’t budge on his impossible negotiation demands, and that the EU won’t negotiate, we will be rapidly heading for no deal. MPs will then have three realistic options. The first is to enact new legislation forcing Johnson to request a new extension to the process. He has insisted that he will not do so, and the government will do all it can to hinder such legislation. A man who is showing himself uniquely contemptuous of parliament may also refuse to obey it. Even if he does, he will go to Brussels and report that he is being forced to seek an extension that the British government does not support. How is the EU supposed to respond in those circumstances? And if it does grant the extension, how can parliament ensure that Johnson accepts it?

MPs could also bring a vote of no confidence in the prime minister. Johnson has, once again, signalled that he is indifferent to such an expression of parliamentary sovereignty. His chief of staff Dominic Cummings has indicated that, in any case, the prime minister would not resign, and could call an election for after 31 October – effectively neutering any opposition to no deal. A court case would almost certainly follow, but the process would be messy and chaotic.

And so the only guaranteed way to stop no deal is to stop Brexit itself. Faced with an unprecedented national emergency, MPs could pass an act of parliament revoking article 50. This would satisfy our “constitutional requirements” specified by the European court when it granted the UK the unilateral right to revoke. It could also be done without government support, as with Yvette Cooper’s bill in April to force an extension. That passed in three days, while this bill would have more than six weeks.

For Tories, in particular, this would carry the advantage of not directly forcing them to bring down their own government. Moderate Conservatives did not sign up to Brexit at any cost and owe Johnson no personal loyalty, while leave-sympathetic Labour MPs such as Lisa Nandy have signalled they would also back such a move. Even if there was no time to clear the bill before 31 October, the EU might take note of the clearly expressed will of parliament to remain.

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Certainly there would be a question of democratic legitimacy. Brexit was enacted by a referendum and should be ended by one too. Parliament could therefore legislate for a subsequent confirmatory plebiscite to establish whether people in fact want to stay in, or otherwise restart the process. MPs could conceivably (though at great risk) put no deal on the ballot paper for the first time. Revocation is the only option now because there is no time for a referendum before we crash out.

The Britain of 2019 is unrecognisable from the country of four years ago. A Brexit that in 2015 meant a Norway-style single market has come to entail our total rupture with every EU instrument, body and law, at any political, economic and human cost. Since the referendum, the Brexiters have refused all compromise. The hardline fringes have hijacked a slim mandate and reinterpreted it in the most extreme way available to them. No deal is the all-or-nothing corruption of a democratic vote, and revocation is its democratic answer. Like every other outcome, it will provoke a sustained political crisis. But in the end it may be the only way to save the economy – and people’s lives.

• Jonathan Lis is deputy director of the thinktank British Influence