For a group of people who urged a step most economists regarded as irrational, some of those who campaigned for the UK to leave the European Union are unusually confident now that economic rationality will hold sway in the exit negotiations.

Many who favoured so-called Brexit are sure that the 27 other EU governments will allow the UK unrestricted access to the reduced single market of 440 million people, figuring they will be eager to have free access to the lucrative UK market of 65 million. Influential German car companies, they insist, will bundle Berlin, and with it the EU, into a trade deal that suits London nicely.