The United Kingdom Elections 2010

[therother]

Funny the Tories weren't more supportive of the idea of AV earlier. Here's a list of seats denied to the Tories which they would of won had a UKIP candidate not been standing.

Two things: a) you are of course assuming that nobody voted Labour or LD as their 2nd choice. Take Bolton West. I'm sure you are right and the vast majority of UKIP voters would vote Conservative second. There are, however, 8,177 LD voters. Recent polls put the split between Labour and Conservative leaning Liberal voters as ~75%/25% Lab/Con nationwide. Assuming that's a fair reflection, this seat would have been solid Labour hold. b) to win a seat with AV, you need a majority of the vote. Conservatives plus the entire UKIP 2nd vote would only give 42.3% of the vote. They would still need to pick up a lot of LD 2nd votes.

This is why the Tories are fearful of AV: they assume that Liberal voters will favour Labour (and Labour voters will favour Liberals in Con/Lib marginals), and so even safe Tory seats could potentially fall. Take Battersea, for instance, where the Tories polled 47.3% of the vote, Labour 35.1% and Liberal Democrat 14.7%, Green 1.1% and UKIP 1%. Even if the Tories gained all the UKIP votes and the Green votes they would still not win the constituency: it would be decided on the alternative choices of the LDs. If they overwhelmingly support the Labour candidate...