The disastrous G7 summit in Canada was a classic display of Donald Trump’s style of “negotiation” — one which combines self-pity, threats, and grandiose and impractical proposals. But just as most of America’s allies recoil in horror at the US president’s trade diplomacy, Mr Trump has found an admirer in Boris Johnson.

At a private dinner last week, Britain’s foreign secretary mused: “Imagine Trump doing Brexit?.?.?.?He’d go in bloody hard?.?.?.?There’d be all sorts of breakdowns, all sorts of chaos. Everyone would think he’d gone mad. But actually you might get somewhere. It’s a very, very good thought.”

It is a very good thought, but not for the reasons that Mr Johnson thinks. There are close parallels between the Trump style of trade negotiation and that favoured by hardline Brexiters such as the foreign secretary. These similarities explain why both men are likely to damage their own causes, creating “all sorts of chaos” without any compensating gains.