The Tories won 307 seats, Labour 258, Lib Dems 57, Other 28.
Of these seats, the Tories got more than 50% of the vote in 130 seats (42% of their total MPs), Labour 80 seats (31%), Lib Dems 14 seats (25%), Others 3 seats (11%).
These are their respective party's rock solid ultra ultra safe seats. These are the sort of seats that need the incumbent party to be having dismal national poll ratings coupled with internal dissent in the local party about a candidate, a co-ordinated unopposed 'independent' and a political earthquake backed by the media for anyone to have any chance of an upset. Maybe 3 or 4 seats a generation would change hands here - your Blaunau Gwent, Tatton sort of seats. These seats will remain very safe even with the introduction of the Alternative Vote system.
Next come the seats in the 45-49% range;
Tories 85 seats (28% of their total MPs), Labour 63 seats (24%), Lib Dem 23 seats (40%), Other 9 seats (32%).
Maybe 5% of these seats would change hands in a generation, the swinging of the political pendulum is unlikely to bother these MPs much though, they are very safe. AV however might make some of them sweat.
So far we have 70% of Tory MPs sitting in either ultra safe or very safe seats, 55% of Labour MPs, 65% of Lib Dems and 43% of Other MPs. (To be fair, in a 2 horse race, one or two of these seats can be tight, but they are few and far between).
I think we can start to see why the majority of MPs are reluctant to see any change in the present system of electing them.
In total 35% of all MPs get more than 50% of the vote. 63% of MPs get more than 45% of the vote. 85% get more than 40% of the vote. So only 15% of MPs are in the fairly marginal seats (below 40% of the vote to the winner. And even some of these can be quite safe because of how the vote splits 3 ways or more). It is the 22% of seats in the 40-45% bracket that will become much more marginal under AV. This will make our elections far more competitive (and ultimately more democratic) if we vote Yes to Fairer Votes in 6 months time.
I know, I am a bit late on this analysis. I was actually hoping someone else would do the number crunching I was looking for (if it is out there on the net in more detail and better presented, please let me know). I painstakingly went through all 650 constituency election results so I may be out by 1 or 2% here and there.
Due to the gerrym..I mean changes to the electoral geography that will happen before the next general election, a lot of this analysis will sadly be difficult, if not impossible to transpose to the new boundaries.
The Tories say it is unfair that at the recent election with 36% of the vote they 'only' got 47% of the seats. That's right, you didn't misread, they are complaining because they only got 15% MORE seats than their voteshare would suggest they deserve. In contrast the Lib Dems got 9% of the seats with 23% of the vote (14% LESS than their voteshare), the Tories however have little to say on this.
The 'NO' Campaign in the forthcoming referendum on how we allocate power, will focus on stuff unrelated to the actual change in the electoral system, they will copy the Tea party success in the US where when you have no facts to support your case, you just make some up and use the media you own to back you up. The 'Yes campaign have got to circumvent this and contact the people locally. Find out where your local group is and give them a hand.