From over the Channel comes the familiar sound of déjà vu. A populist politician has identified a complex problem, found someone to blame for it, and come up with a solution that will simultaneously win votes and make things worse. It’s the end of the summer and the migrant camps at Calais have doubled in size from an estimated 4,500 people in June to 10,000 now.

Presidential hopeful Nicolas Sarkozy wants the Le Touquet agreement – the one that lets the UK control its border in Calais and the French control theirs in Dover – to be revisited in the wake of the Brexit vote. He wants the UK to open migrant "hotspots" in Calais – one-stop shop asylum processing centres of the kind set up in Greece and Italy to deal with the massive numbers of asylum seekers.

It’s widely agreed that this will make the problem worse, not better, for both France and Britain. According to Sir Peter Ricketts, the former British Ambassador to Paris, Calais hotspots for British asylum seekers would act like “a huge magnet, pulling thousands and thousands more migrants in to Calais to chance their arm, and it wouldn’t help the problem of the thousands and thousands of migrants already at Calais”.

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Mr Sarkozy, of course, probably doesn’t actually want hotspots at Calais. What he wants is to win next year’s presidential election. No one in the UK needs another lesson in the consequences of populism. Never in recent decades has a Western democratic nation had a more potent demonstration of it. Prices going up and wages going down? Corporations getting richer while you’re getting poorer? Immigrants taking your job and spending your benefits? Doesn’t matter if it’s true – just blame the EU.

Mr Sarkozy is an effective politician, and over the coming years he will certainly not be the last would-be European leader on the campaign trail to look at his nation’s problems and decide there’s votes to be had in blaming Britain. And for the Brits, this will have consequences. Throughout history, the European continent has been no stranger to populists. Don’t imagine other nations around Europe don’t have politicians just as vain, just as dismal, just as shameless and just as pyrotechnically destructive as, for example, Boris Johnson.

Mr Johnson is not the first politician to stare down the barrel of a backfiring promise, of having to stick to a promise he never foresaw being forced to keep. If you think the mere fact that hotspots are a bad solution for France, a bad solution for Britain and a bad solution for asylum seekers should be sufficient for them not to happen, then you’ve not been paying very close attention for the past two months.

Right across Europe, in the coming years, there will be political capital to be made from promises to screw the British, who will quite rightly be blamed for the sudden perception that Europe is an unstable continent (it might not be 100 per cent Britain’s fault, but it will still be blamed).

In the weeks following the referendum, many people asked why it was only now that the most potent Remain argument was suddenly being made – that EU countries will punish Britain to save themselves. In Brussels and Westminster circles, this point was well known. (Angela Merkel came close to making it once, but the UK media was far too interested in Steve Hilton’s Stab-Dave-In-The-Back book tour to listen). In the Remain campaign’s defence, the argument that if we don’t stay in the EU the EU will screw us is a difficult one to make. And in any case, they had too much on their plates getting that crucial Beckham endorsement.