UK's Lousy First Past the Post Electoral System

The UK is having an election in 20 days.

Current Polling (Averaged)
Labour - 27% - 267 seats
Conservative - 33% - 255 seats
Liberal Dems - 29% - 97 seats

Labour is in third place in the polls, but first place in the seats! Some of this bias makes up for the natural bias in electoral systems to the rich (as people who vote more often). However, in this case, the UK goes way beyond reversing the bias.

Hopefully the Liberal Democrats will hold the balance of power and be able to push a move to proportional representation (aka Single Transferable Vote).

On second look, it turns out

On second look, it turns out that the prediction above assumes a Uniform National Swing (party support changes by the same percent in every riding). And a non-uniform swing could provide very different results. Estimates show the Conservatives winning 30-50 more seats than the uniform swing would predict (due to regional differences, a larger swing in competitive ridings, retired incumbents, etc).