12% - Lib Dems get that sinking feeling

Today's news that the Lib Dems are at just 12% in the opinion polls caused Labour's David Cairns to scoff that Clegg's party would get less MPs under the AV system they joined the coaltion for than they would under the current system.

While we all contemplate the Lib Dems disappearing down the political plug hole I tried to work out if that joke had more than a grain of truth about it. It does, as it happens.

I also came across this Scottish data that Jeff at the SNP Tactical Voting blog has scraped from the Guardian website.

There's some analysis over on his own site but I'll just reproduce the figures here which show how the 2010 general election result in Scotland would have looked under different voting systems. Kind of academic now, but kind of interesting too.


2010 Westminster General Election result:

Labour – 42% (41 seats) 70% of seats
SNP – 20% (6 seats) 10% of seats
Lib Dems – 19% (11 seats) 19% of seats
Conservatives – 17% (1 seat) 2% of seats

Total variance from true proportional representation = 53%

Under AV, constituency candidates ranked and votes redistributed until 50% winner is declared.

Labour – 42% (41 seats) 70% of seats
SNP – 20% (5 seats) 8% of seats
Lib Dems – 19% (12 seats) 20% of seats
Conservatives – 17% (0 seats) 0% of seats

Total variance from true proportional representation = 57%


Under AV+, single member constituencies with top up regional MPs.
Labour – 42% (36 seats) 61% of seats
SNP – 20% (9 seats) 15% of seats
Lib Dems – 19% (11 seats) 19% of seats
Conservatives – 17% (3 seats) 5% of seats

Total variance from true proportional representation = 36%

Under STV, multimember constituencies with candidates needing a quota not outright majority.
Labour – 42% (28 seats) 47% of seats
SNP – 20% (13 seats) 22% of seats
Lib Dems – 19% (11 seats) 19% of seats
Conservatives – 17% (7 seats) 12% of seats

Total variance from true proportional representation = 12%


Grateful thanks to Jeff (Btw Jeff, of course I voted for you in the blog awards, and ever other Scottish, Welsh and Irish political blog I could think of).