Leading Conservatives have hit out at former chancellor Philip Hammond’s “ridiculous” claim that Boris Johnson’s Brexit policy is being influenced by wealthy backers from the City who have bets on a disruptive no-deal Brexit.

Hammond, chancellor of the exchequer between 2016 and July, wrote in The Times on Saturday: “Boris Johnson asserts, ever more boldly, that we will leave the EU with or without a deal. But as his sister has reminded us, he is backed by speculators who have bet billions on a hard Brexit — and there is only one outcome that works for them: a crash-out no-deal Brexit that sends the currency tumbling and inflation soaring.”