Simon Osborne, the society's spokesman, said yesterday that the supplementary vote (SV) was likely to have produced a minority Conservative government at the last election. In future contests, however, it was quite possible for Labour to gain an overall majority with 38 to 39 per cent of the vote using the system - although the party would need bigger swings in some areas because of impending boundary changes that could hand the Tories between 12 and 18 seats.
Mr Osborne said that the only near equivalent of SV that the society's researches had unearthed was the presidential vote in Sri Lanka.
On the basis of research by the London School of Economics and Rowntree Trust after the election in April last year, Mr Osborne roughly estimated that an 'alternative vote' system similar to SV would have seen John Major three seats short of an overall majority, raising the prospect of a minority Conservative government ruling for six or seven months until the next contest, or a possible deal with the Ulster Unionists.
Labour would have dropped 10 seats and the Conservatives 13, while the Liberal Democrats, the SNP and Plaid Cymru would have picked up an additional 17, 3 and 1 respectively. But Mr Osborne emphasised that the Tories would have done relatively well under any electoral system - the swing from the Tories to Labour was only 2.5 to 3 per cent, and the Conservatives polled 3 million more votes than Labour.
Dale Campbell-Savours, Labour MP for Workington, who drew up the SV system, questioned Mr Osborne's calculations. 'There would have been a distinct possibility of a minority Labour Government,' he said.
Alternative systems, such as the additional member system (AMS) used in Germany, and the single transferable vote (STV), would have produced far greater advantages in seats for the Liberal Democrats in the last election (116 and 101 respectively), while still leaving the Conservatives as the largest party, Mr Osborne said.
In general, the chances of non-coalition government were 'much reduced' under 'pure' proportional representation systems, he added, unless a party achieved 49 to 50 per cent of the vote. That happened in 1935 to the Conservatives and in 1951 to Labour. But Labour still lost out in 1951 because the Conservatives won more seats.Reuse content