Boris Johnson and his advisers are reportedly ready to tell the Queen she cannot sack him, even if he loses a no-confidence vote in the Commons later this month - a plan ridiculed by lawyers and historians.

It comes as the Court of Session in Scotland decides this morning whether a clerk or another government official can sign and send a Brexit extension letter on the prime minister's behalf if he refuses to do so.

With talks in Brussels thought to be close to collapse, Mr Johnson spoke to his Irish counterpart Leo Varadkar over the phone on Tuesday night and the pair are expected to meet in person later this week.

What can the Queen do if Johnson refuses to resign if asked? Abdicate? That should send BoJo's approval numbers skyward amongst his own Tory faithful... And would a King Charles be any more amenable?

Index of Frank's Diaries