“It had taken a long time to arrange this,” says David Lidington, Theresa May’s former de factor deputy, recalling his first formal meeting with Sir Keir Starmer in the cross-party Brexit talks last year.

“He had to be accompanied by two minders from Corbyn’s office, including Seumas Milne. And it was like when you see an ambassador from one of the authoritarian countries – Russia or somewhere – and they come with a minder who’s clearly taking note of