Lord Ashcroft’s latest poll of Liberal Democrat battleground constituencies suggests I may need to revise my classification of the six species of Lib Dem MPs.

His findings point to the existence of a few more “trend-defiers” than I previously identified.

Along with Eastleigh and Sutton & Cheam, both already on my list, Ashcroft’s polls imply the Lib Dems may also hold on to Cheadle, Eastbourne and St Ives.

St Ives is particularly eye-catching, as the Tories need a swing of only 1.9% to take the seat.

I’d rated St Ives as “doomed”, Eastbourne as “condemned” and Cheadle as “dicey”.

Bill left a comment about Cheadle on my ‘six species’ piece, saying that he wouldn’t be surprised if the Lib Dems hang on to the seat – and this new poll bears him out.

Lord Ashcroft has also found that the Lib Dems and Tories are currently tied in Cornwall North (another of my “condemned” seats) and Torbay (“dicey”).

It seems the party is presently defying a uniform swing away from its MPs and towards the Tories. This could mean the election result, while bad for the Lib Dems, may not be quite the whitewash the national opinion polls have been implying.

Things are less rosy for the party in seats where Labour is the main challenger, however.

The Ashcroft poll suggests Labour would gain Cambridge, Cardiff Central, Hornsey & Wood Green and Redcar: all seats that need swings of over 4% to change hands.

I’m especially struck by Cambridge, which I’d classified as a dependably safe seat and where Julian Huppert has a majority of 6,792.

Labour is also forecast to jump from third to first place and gain Watford, where the Tories currently have a majority of 1,425 over the second place Lib Dems.

What with the SNP now in realistic contention for Gordon, the Liberal Democrats will head to their conference this weekend (in Glasgow, by a delicious twist of circumstance) fearing even more of a lopsided wipeout.