If, say, 70% of the voters vote for a party that gets more than its fair share of the votes they will want to keep that advantage.

Is that why Labour supported AV, Martin?  After all, I don't think any Labour Government other than the landslides of 1948 and '97 has actually had a majority of the popular vote.

It's already got to the stage that the government is told what to do by the banks and by big business.

Not to mention the Trades Unions, Martin: don't forget their immense influence whenever Labour has been in power, through their sponsorship of various candidates - something that doesn't exist with Tory or Lib-Dem candidates.