The BBC has been stepping up the pressure on Downing Street over the show-piece live referendum debate at Wembley stadium. Sources with intimate knowledge of the Beeb’s preliminary offer to Craig Oliver claim they proposed a 4 v 4 debate in front the audience of 12,500, suggesting the following line-up:

Remain: George Osborne, Alan Johnson, Tim Farron, Caroline Lucas

Leave: Boris Johnson, Nigel Farage, Iain Duncan Smith, George Galloway

This is a hardball proposal, and one which Downing Street is sure to shoot down. Sources say the BBC made the deliberately provocative bid as “revenge” for Oliver’s obstinate negotiating stance over last year’s election debates.

The BBC are also offering a 1 vs. 1 debate and – in the knowledge that No. 10 will refuse to pit Cameron against Boris – so are suggesting Dave and Gove are put forward in a Question Time style setting. This would meet Downing Street’s condition that they are not on stage arguing with each other at the same time. The wrangling is hotting up again…

UPDATE: A BBC source gets in touch to kick back: “This is total, 100% nonsense, including the format and the names”. Curiously the Telegraph has the very same names. Though this is a strong denial from the Beeb and an all-male Leave line-up would be very unlike Auntie…