Chequers, as the journalist Chris Deerin has pointed out, goes pop. Which wry and funny as it is for those of us of a certain age will not be cheering up Theresa May. Because the EU summit in Salzburg has been a personal catastrophe for her. And worse than that, it was an avoidable catastrophe. Because every EU expert bar those she employs in Whitehall has been saying very loudly for weeks that the trade and commercial proposal in her Chequers Brexit plan would never win favour among the EU 27.
So the question is why she waited to have that so publicly and humiliatingly stated by the EU's president Donald Tusk today, rather than quietly acquiring some wriggle room over recent days. She's also rejected the EU's proposal to keep the Northern Ireland border with the Republic open – because, in her estimation, it would undermine the integrity of the UK – but won't tell them what her revised proposal may be, though she insists she has one.
Neither she nor EU leaders want a hard no-deal Brexit. But probably the only way for her to avoid it is to eat the humblest of humble pies and jog back to the deal her departed Brexit secretary, David Davis, naively thought he had been mandated to negotiate – a more conventional free trade agreement based on Canada's deal with the UK.
And maybe she could get that through the House of Commons, if her Remainer MPs were terrified into believing that the alternative to backing it would be a general election – which they assume Corbyn would win (whatever opinion polls may indicate).
That said, Canada still wouldn't solve the Irish border conundrum. Which means that the UK may not be in a position to sign a withdrawal agreement – and that, in turn, means a no-deal Brexit remains a live possibility, even a probability.
A couple of things follow from all of this:
1) May will emerge as unique in the annals of history if she survives as PM much longer in the face of setbacks on this scale
2) If all conventional roads lead to a hard no-deal Brexit, the notion of Parliament exerting control and forcing another referendum on us would begin to look not wholly fanciful.
Brussels officials say that Barnier, Juncker and Tusk wanted to help May turn Salzburg into a stepping stone towards a deal, rather than an impasse.
"We were so ready to help" says one. But she and her officials made two serious miscalculations, they say:
1) She was too aggressive, both in her article setting out what she wants in the German newspaper, Die Welt, and at last night's dinner;
2) She was naive in thinking she could appeal above the heads of Barnier, Juncker and Tusk to EU leaders, when those leaders have more pressing issues on their plates and delegated the substance of talks to Barnier for a good reason.
Which means May has driven Brexit talks into a dark cul de sac, and goodness alone knows how she'll get her – and the UK – out of it.
This post originally appeared on Robert Peston's Facebook page