The Guardian has an interesting piece on how proportional representation would have changed the 2010 election, comparing the results with those which would have occurred under preferential (or alternative) voting, the "AV-plus" system of broken MMP, and STV. The results are nicely summed up in the graphic below:
(Click for lager version; image stolen from the Guardian)
Of course, two of those systems aren't proportional - preferential voting isn't, and AV-plus is deliberately broken to prevent it. But it still shows how unfair the results are. It also shows why Labour and the Tories are willing to look at AV, or even AV-plus, but not actual proportional representation: because the latter would end forever their cosy little duopoly on power, which is maintained only by stacking the electoral system to produce an artificial and undemocratic outcome. The last time a UK government was supported by a majority of voters was 1931. More recently, governments have been supported by as little as 35% of voters. And that simply is not democracy.
