Election Strategy

My election strategy is changing all the time, but currently it looks like I'll vote for the LibDems as usual.
In Cambridge City we actually have a Trade Union & Socialist Coalition candidate, who would certainly get my vote in the real world.
But this being politics I'm thinking that it may be better to attempt to ensure a LibDem victory so that they can make some headway towards PR before the bond markets up the interest rates and bring them crashing down.
Then at the next election votes for the TUSC are likely to count for more and maybe we can start to get the country run for the people rather than for international finance.