When is the 'next' PM actually settled? Is it when the Queens Speech has been voted through?
Betfair (and Paddy Power) have been quite vague. Initially it was "when the Queen give's assent to the formation of the first ministry" a term which doesn't seem to exist anywhere on the whole internet.
They seem to have stopped using that now. I don't think it is the Queen's Speech being voted through specifically, but I believe when it is, there is a background formality whereby the Queen agree the government can proceed.
The DUP have, today, indicated that they will vote for the Queen's Speech even if their deal has not been complete with the Tories so I'm slightly surprised at the big drift in May's price. I can only assume it's to do with negative sentiment relating to her avoidance of the families of the fire.
I'll be honest, the price seems ridiculous value to me. I don't think the Tories will overthrow her now, although I'm sure many want to, simply for self-preservation. Why would a Tory MP want to go back tot the electorate now?