Withholding the cash, scrapping the Northern Ireland backstop, guaranteeing the rights of all EU citizens in Britain while stepping up preparations for a No Deal “disruption” in the wake of no deal are among measures the government would carry out if he was elected leader of the Conservative party, he said.

Failure to deliver Brexit, with or without a deal, by the October 31 deadline threatened the Tory party’s very survival, he warned. He said he thought it “extraordinary” the UK agreed to write the so-called divorce cheque before having the final deal signed.

“I think our friends and partners need to understand that the money is going to be retained until such time as we have greater clarity about the way forward,” he said in an interview with the Sunday Times newspaper. The money, he said, was a “great solvent and a great lubricant” in getting a good deal.