I am a strong supporter of proportional representation because I believe that a parliament that mirrors how people vote is vastly better than one which doesn’t.
That said, it is utterly hopeless to think about a change to the electoral system right now. We are at the fag end of a much loathed government, and anything which they touch will be fatally stained.
If Cameron wins a working overall majority next year, PR will again be off the agenda. However if the parliament is hung and shows up absurd disproportionalities (e.g. the SNP winning more seats than the Liberal Democrats!), then perhaps we are in with a chance.