“There are now lots of voters who should be instinctive Tories who feel very poor in a way they haven’t before. And instinctive Tories feeling poor is very bad news for the Conservatives,” Mr Dorrell said.

“They are what I would call ‘Tebbit Tories’, who would admire Margaret Thatcher. These are people who have started their own small businesses, plumbing firms, electricians, who are now saying they are unsure how they will survive next year.”