During the Brexit referendum campaign, Jeremy Corbyn put his level of support for the European Union at no more than "seven to seven and a half out of 10".

The BBC obtained documents indicating that Corbyn's office sought to delay and water down the Labour Remain campaign. Sources suggested that they were evidence of "deliberate sabotage".

A week after the vote, Labour grandee Alan Johnson tore into the party's leadership over Brexit. The head of Labour's EU Remain campaign complained that "the lukewarm approach by Jeremy was bad enough but there is no doubt in my mind that at least three of his closest associates in the leader's office were actively undermining the party's efforts".

And Lord Mandelson told the BBC: "We were greatly damaged by Jeremy Corbyn's stance, no doubt at all about that. Not only was he most of the time absent from the battle, but he was holding back the efforts of Alan Johnson and the Labour In campaign. I mean they felt undermined, at times they felt actually their efforts were being sabotaged by Jeremy Corbyn and the people around him."

But top Corbyn ally Richard Burgon painted a rather different picture when he appeared on BBC’s Question Time.

The shadow justice minister made the audacious claim: "Labour did campaign, as everyone knows, passionately, for a remain and reform agenda."

His comments were met with derisive laughter by the man sitting next to him, David Cameron’s former communications chief Craig Oliver. And by most of the audience.