Guido has an interesting tidbit on the Lib Dem strategy:

Nick Clegg says he is shifting resources to target what they see as the 50-most winnable Labour seats, pouring efforts and campaigners into fighting Gordon.

This is a sensible strategic move in the face of the reality of the polls, a change of government won’t happen if LibDems and Tories swap seats, a change of government will only happen if the LibDems and Tories take seats from Labour.

This sounds like Nick Clegg is slightly more ruthless than I had given him credit for: he seems to be wanting to pounce on Labour and take over as Britain’s second party.

One of the strange things about Labour’s decline is that the Conservative Party has so far been the sole beneficiary in England. Lib Dems have seen their support slip to the Cameron juggernaut just as Labour have. In the past week or so, Lib Dems have finally started polling higher than Labour in marginals, but more thanks to Labour’s astronomical nosedive, not to any great rise in support for the yellow corner.

A cynical thinker might suggest that it would be worth letting the three-way-marginal Watford go after all: the Lib Dems probably need the seat more than the Tories, and it could aid in pushing Labour right down into third place.

I would never suggest such a thing, of course.