Last year, Theresa May sidelined her then Brexit Secretary, David Davis, and effectively put Olly Robbins, her Europe adviser, in charge of the negotiation with the EU. And in July, she dropped Davis’ plans, later published by this site as the Alternative Brexit White Paper, and took up the Chequers proposals. This U-turn persuaded both him and Boris Johnson to quit the Cabinet.

The Prime Minister would not have risked those resignations had she not been assured that Chequers was negotiable. Robbins himself confirmed the point during this week’s Panorama, in which the Prime Minister set out her case. The expectation in Downing Street was that the EU would formally declare at Salzburg that Chequers was a practicable basis for a deal. It was for this prize that she was willing to lose two of her most senior Ministers, alienate a sizeable chunk of her party, risk a leadership challenge, and face down her critics at the forthcoming Conservative conference, presumably declaring as she did so that “the lady’s not for turning”.

This morning, May is left clutching not that trophy, but a wooden spoon. Donald Tusk put Chequers to the sword in half a sentence: “the suggested framework for economic co-operation will not work.” The EU27 appear to have concluded that the Prime Minister compromised last December when a draft Withdrawal Agreement was first produced, and will duly compromise again to settle on one of its three preferred outcomes: Norway, Canada (plus the backstop) or the junking of Brexit itself. The Bond film-style setting for the summit’s final dinner looked like a round-table for Ernst Stavro Blofeld. Emmanuel Macron duly dropped the drawbridge and fed May to the piranhas.

Which leaves her with only one strategic option.

Before describing it, we must first dismiss two others that are closed to her. The first is simply to press on with Chequers, declaring that “nothing has changed”. This would leave the Prime Minister in the exposed position of being just about its only supporter. The harder Brexiteers don’t like it. They prefer Canada. The softer ones don’t back it, either. They want Norway. Nor, as far as briefings and arithmetic will tell, is there a natural majority in Cabinet for Chequers. Sajid Javid and Liam Fox went their separate ways during the EU referendum, but both are united in preferring to take the Canadian route. And now the EU has dispatched it. Chequers has no mates. It’s a dead parrot. May risks collapsing her leadership if she claims in Birmingham that the bird is really pining for the fjords.

The second is Norway. There may come a point at which Conservative MPs, faced with a complete and final collapse of the talks, conclude that the consequence will be either No Deal, which they decide is unmanageable, or No Brexit, which would defy the democratic will of the British people, expressed in the biggest-ever vote in our history, and endorsed by both the main parties in last years’ election. At that point, the EEA port-in-a-storm option would be on the table. But a stark fact endures: voters simply aren’t prepared for this course. The Prime Minister has expressly ruled it out. The Commons has voted against the EEA within the last year. Any switch to it would require a new Conservative leader. It would need an election mandate, too. That would risk putting Jeremy Corbyn in Downing Street.

Which leaves only one road for May to take. The route to Canada Plus Plus Plus, as Davis christened it, is not an easy one. A daunting obstacle sprawls across it: the Northern Ireland backstop. But if – we repeat if – that barrier can be climbed, negotiated, ducked or swerved, Canada is good deal more straightforward than Chequers. The latter’s complex customs proposals, its plan to separate manufacturing and services, its challenges to the theology of the Single Market – all would be swept away, to be replaced by a single big trade-off: Single Market access v more economic freedom. The Commons might well vote a Canada plan down. But a Norwegian one is closed to this Prime Minister. And Chequers is a dodo, as we have seen.

But if the Prime Minister takes the one strategic road now open to her, she has a further choice to make.

She could let the EU come to her with Canada, in effect, telling her Party Conference. “They’ve rejected our proposals. Now it’s up to them to advance theirs. All I can tell you is: we’re sticking to Brexit. And we’re ready for No Deal.” Or she could go to the EU with Canada, get on to the front foot, make a virtue of necessity, and say in Birmingham. “I’ve tried. I’ve really tried. But the EU has rejected our plan. So here’s one that it accepts in principle, which most of you want anyway, and which stands a fighting chance of getting through the Commons.” The question then for the more hardline of the Soft Brexiteers – if we can put it that way – is whether they would really be prepared to vote down any Canadian-based agreement, risk the No Deal they abhor, and doubtless force May out while they’re at it.

We believe that the Prime Minister should try to shape events rather than let them shape her, and perhaps dispense with her altogether. None the less, doing so would mean swallowing a lorryload of humble pie. She would have to concede that Davis called the EU’s reaction to Chequers right – and she lost both him and Johnson for nothing, other than a summer of differences and divisions that further weakened her government. But for every downside there is a potential upside. Party conference could be turned into an occasion for healing rather than bloodletting. The two former Cabinet Ministers and Steve Baker could support May from the conference platform, if they are willing. Downing Street would be in position to hug the ERG close. We dare to dream that Birmingham could become a UnityFest.

Making this option work, though, would mean change at Number Ten. We don’t blame Robbins for following his mistresses’ instructions: after all, he’s a civil servant, and politicians ultimately decide. But Dominic Raab needs to take unambiguous charge of the negotiation. Downing Street should draw more for support on Fox’s trade department, the most engaged in a trading future for Britain.

May needs more Brexiteers near the top of her staff: Robbie Gibb is one of very few. Number Ten’s Europe Unit requires a shakeout. Graham Brady, Chairman of the 1922 Committee, is an irenic Leaver. The Prime Minister should draw on his advice. Around the black cloud of Salzburg one can glimpse a silver lining.