Why was the Tory defeat in 1997 so heavy? One of the reasons was that the anti-Tory vote tended to coalesce around the candidate most likely to defeat the Tory in each place. Tactical voting in 1997 cost the Tories 30 seats, turning a bad defeat into a catastrophe.

Last night provides evidence that this is happening again, that in British politics there are now two blocs, the Tories and the anti-Tories.