It's why the two (currently) biggest parties like our First-Past-The-Post system and why the LDEMs hate it. But if we changed it to full Proportional Representation, as the LDEMs want, we would never have a majority government again and would end up with a) very minor parties (Greens, BNP) wielding excessive power, b) a very weak government who can do nothing except provide Bread and Circuses in a desperate attempt to stay in power but no "real" rule and c) possibly several governments a year when the Bread and Circuses aren't enough.

If you wanted to follow some kind of PR system, it would have to be weighted so that 25%-40% made a very big difference in the number of seats

I don't want there to be some kind of PR system. I think it would be a really bad idea. Brown The Inert wants the House of Lords replaced by a "fully elected second chamber", but he wants one elected by PR, so it will never have any true mandate or power.

@speaker to Aliens - If you want strong government shouldn't we just do away with elections all together? TGM has laid out how the current system could result in a hung government, if we are going to have a hung parliment, surely it should be proportionately hung?

LIBERAL DEMOCRATS WIN A POLL:
BPIX: CON 31%(-7), LAB 28%(-3), LDEM 32%(+12)

ComRes: CON 31%(-4), LAB 27%(-2), LDEM 29%(+8) (conducted yesterday)
ICM: CON 34%(-3), LAB 29%(-2), LDEM 27%(+7) (mostly pre-debate fieldwork)
YouGov: CON 33%(nc), LAB 30%(+2), LDEM 29%(-1) (Tonights daily poll)

Random error means that any party can win a poll without any actual change.

@Maniac, that argument doesn't work, because speaker can claim a balance of harms: either extreme of perfect proportional representation or dictatorship is undesirable, the best system is a kind of mid-way point.

Are these real polls?

Yes, they are. What the polls say at the moment doesn't mean a great deal, however, and there is huge scope for change before the election. If the polls by some fluke do keep to these levels it will be interesting to see how many Clegg supporters have a change of heart once they get to a ballot box. I'd guess quite a few.

YouGov: CON 32%(-1), LAB 26%(-3), LDEM 33%(+4)