In the 2005 UK general election the governing Labour party won 35.3% to the Conservative party's 32.3% and the Liberal Democrats' 22.1%, yet Labour secured 356 parliamentary seats to the Conservatives' 198 and the Lib Dems' 62. Many people assume the result is unfair, but is it and would a system of proportional representation be any better?
I would argue that our system of 'first past the post' is fair, and in fact much more so than replacing it with one using PR.
In the United Kingdom we district our national election into (currently) 646 individual constituencies, making each national battle one comprised of hundreds of much smaller ones. A big advantage of this system is that - in theory at least - every voter in each of the constituencies has the chance of casting the winning vote for a party's representative. For example, in the 1997 election for the seat of Winchester the winning MP's margin of victory was just 2 votes. Another example from a country that districts its national election, the US, is Florida in the 2000 election where George W Bush beat Al Gore by just 537 votes.
Democracy isn't only about giving people equal power in an election (after all, in a dictatorship each voter has equal power of 0) but about giving each person as large an equal share of power in deciding the outcome of an election as possible. The people of Winchester or Florida would have had virtually no chance of having the sort of impact on their respective elections they had if their votes had been diluted into a sea of many millions of other votes, as would happen under a system of PR.
Elections are always lopsided, and the power an individual voter has to make a difference to the election's result goes down the more uneven an election is. Breaking a nationwide election down into lots of smaller localised elections balances out some of this lopsidedness, maximising the individual voter's power.
There are other reasons to support a system of 'first past the post' over PR. Labour may only have won 3% more of the national share than the Conservatives at the last election, but they won seats all over the country, whereas the Conservatives relied on the South of England for much of their support doing particularly badly in the North, Wales and Scotland. First-past-the-post prevents politicians from simply wooing a majority bloc at the expense of minorities.
What's more, PR almost never results in a majority government meaning that the parties have to go behind closed doors and haggle with each other over forming a coalition. The public have no say in these backroom negotiations. With no constituency link between members of parliament and the voters, the real power lies with those parties who can successfully jockey for position in a coalition government.