In an interview with BBC Radio 4's Today programme, he said: "As soon as you stop wasting time trying to negotiate the unnegotiable – some special trade deal with the European Union – it is possible to have a relatively quick exit.

"Don’t go after this will-o’-the-wisp of a special trade deal with the European Union, which they will never give us, because other countries will ask for special deals of theirs."

Lord Lawson said that Britain could repeal the the 1972 European Communities Act, convert all European laws and regulations into British ones, exit quickly and then start the process of deciding which parts of the rule book to keep post-Brexit.

His hard-line stance on the Brexit negotiations is likely to be at odds with that of the Government, which has tasked civil servants with assessing the impact of different post-Brexit scenarios.