Could Labour leadership coup end up in the courts?

This is how I understand an attempt to unseat Jeremy Corbyn would have to work.

If the Parliamentary Labour Party discusses the current No Confidence motion tomorrow evening, then MPs will vote during the course of Tuesday.

But even if Jeremy Corbyn loses that, he doesn't have to go - and Emily Thornberry, the shadow defence secretary, tells me he won't.

To get rid of him, 20 per cent of the Parliamentary and European Parliamentary Parties - 50 MPs and MEPs - need to write to the Labour General Secretary nominating a challenger (if there is a vacancy at the top the number falls to 15 per cent, or 38 signatures).

A former Labour minister tells me just such a challenger is in place. This, as we can see today, is an organised coup.

The big question then will be whether or not Jeremy Corbyn also needs 50 nominations, or whether he gets on the ballot automatically.

This is where it gets messy. I understand the Labour Leader's office has sought legal advice on this and have been told that he will get on the ballot automatically.

But other members of the party have been given conflicting legal advice.

Could this end in the courts?