The likely effect of boundary changes
In the last few days there has been quite a bit of attention given to a projection of what the possible impact of the constituency changes might be from Lewis Baston. Most attention has focused upon the projection showing the Lib Dems suffering particularly badly, while Labour don't do that much worse than the Conservatives. Overall Baston has the Conservatives losing 15 seats, Labour 18 seats and the Lib Dems 14 seats (note that this is slightly different from the figures in the Guardian yesterday, as the projection for Warrington has changed - orginally they had a change from a North/South split to an East/West split, now they have a far simpler solution which moves just one ward).
The way the projection has been done seems perfectly valid to me - Baston just seems to have taken the known facts (things like the Isle of Wight having two seats, and the regional distribution of seats in English which the boundary commission have said they'll stick to unless there are really compelling reasons to cross regional boundaries), then used educated guesswork and knowledge of the sort of things boundary commissions have done in the past to come up with a plausible distribution of seats that fits within the rules.
However, the important caveat is that it is only one of many different possible distributions of seats that might emerge, and some will be better or worse for other parties. The political parties will have done their own projections of possible outcomes, and over on the Vote UK discussion boards there are several people putting forward suggestsion just for fun. I've played about with possible seats distributions myself, and come up with different projections (I did ponder doing something along the lines of what Lewis has done, but never got round to doing it for the whole country). My own expectations based on playing about with possible distributions are that the Conservatives are likely to do considerably better than Labour, but that the Lib Dems are indeed likely to do surprisingly badly. Of course, until mid-September when the first provisional recommendations are published it can only really be speculation.
A second caveat worth noting is one Mark Pack makes here. Notional voting figures for new boundaries only show how the votes would have been totted up if people's votes at the last election had been counted in the new boundaries, not how people would have voted at the last election on new boundaries (and certainly not how they'd vote now). The notional figures will look bad for the Lib Dems because the Lib Dems often have seats that are little islands of concentrated support, which will have territory from non-Lib Dem seats brought into them - while the people in those seats may not have voted Lib Dem last time in a seat that wasn't a viable Lib Dem target, they may have done in if they had actually had been in a Lib Dem target. (of course, on present levels of support boundary changes may be the least of the Lib Dems problems!)
Meanwhile tonight's YouGov/Sun voting intention poll has topline figures of CON 36%, LAB 44%, LDEM 8%. That's the highest Labour lead YouGov have shown since April. I expect it'll turn out to be something of an outlier, but it further underlines the impression that the average lead in YouGov's polls is heading back up to 6 points or so after having fallen down to 2-3 points after the local elections.
