Guardian/ICM poll: Lib Dems set to gain at Labour's expense
To stop Cameron and the Tories pillaging the country
If your constituency is a Conservative v. Liberal Democrat marginal vote Liberal Democrat even and especially if you are a Labour supporter.
If your constituency is a Labour v. Liberal Democrat marginal (like Hampstead and Kilburn) vote Labour even if you are a Liberal Democrat supporter.
In Hampstead and Kilburn a vote for the LibDems Ed Fordham is a vote for a Conservative goverment. Therefore the thing to do here is to vote for Glenda Jackson.