I’m no longer doing the regional swingometer: I trust people to agree with me that tactical voting is more interesting.
I have updated the tactical one so that you can look up current seats by who won the election last (MP’s name).
In the meantime, I have done a little research into how the Tactical voting went in 1997. The way I analyse it: if Conservatives lost votes in a seat and Labour gained votes, then a non-tactical vote would be Labour only gaining as many votes as their share of the non-Tory vote in 1992 would lead you to expect in that seat. Remember that in 1992 Labour won 34% and the Tories 42%, so Labour ought to expect 34/58 = around 59% of any migrating Tory votes.
I found that they won 86% of the Tory votes altogether – which indicated that they were more successful than the other parties on average over 1992 -1997 (remember, the Liberal Democrats fell from 18 to 17%. There was a Labour surge). But in those seats where Labour were 2nd in 1992, they garnered 103% of the Tory loss in votes.
The Lib Dems managed to husband their resources with similar skill. Yes, over all seats they picked up 23% of the votes that Conservatives lost, as opposed to 32% that they ‘should’ have got basis their (strong) 1992 performance. But in seats where they had been 2nd in 1992, they picked up 34% of the votes that fell from the Tories. Still, in those seats, they should have picked up 62% of the votes, because they had three fifths of the non-Tory vote. The Labour Surge hurt them too.
However, in seats where they were less than 20% short of the Conservative incumbent, they picked up 47% of the Conservative votes. Labour voters spared them the surge in those seats – a clear sign of tactical voting.
I would be amazed if the same ‘get them out at any cost’ spirit was in place now.