Labour gained, too, from Lib Dem switchers in number of the marginal seats they first won at the last election, notably Edgbaston in Birmingham and nearby Rugby and Kenilworth where Labour's Andy King increased his majority in the teeth of a strong Tory effort to dislodge him.
But tactical voting remains a minority pursuit. Its effects are hard to disentangle from the special efforts the party themselves put into certain seats, notably Romsey. Dr Steve Fisher of Nuffield College, Oxford, said there had been no "systematic increase" in tactical voting, despite the efforts of Billy Bragg in Dorset and a number of online voting swopping sites.
There is little evidence that online vote swapping made any significant difference anywhere. Tactical voting may have helped oust Tory Ian Bruce in Dorset South but failed to unseat Oliver Letwin in Dorset West seat or win Dorset North for the Lib Dems.It did not dislodge such vulnerable Tories as Gillian Shephard in SW Norfolk.
Lib Dem party officials blamed their own campaigning in Dorset West. They are likely to hold a series of such inquests in days to come.
Some evidence for the absence of tactical voting comes from the failure of Jackie Ballard to hold Taunton for the Lib Dems. She lost 1.44% of the vote compared with 1997 while the third place Labour candidate increased his share by 1.43%.
