The Rallings & Thrasher national vote share projections based on local by-elections for May 2 locals. Changes on 2009 twitter.com/MSmithsonPB/st…

— Mike Smithson (@MSmithsonPB) April 21, 2013

The Sunday Times today publishes the annual projection of national equivalent national vote share for the May local elections based on the performances of the parties in local by-elections.

This, of course, is the production of the duo of Professors Colin Rallings and Michael Thrasher from the University of Plymouth. They, alongside Professor John Curtice, are due to take part in a briefing sessions in Westminster on Wednesday morning when hopefully we’ll get more details and more detailed projections.

One thing that will complicate matters this year, and provide some good cover for the spinners from parties likely to lose out, is that about a third of the seats coming up have been subject to boundary changes since they were last fought in June 2009.

Generally the Press Association only records gains where the boundaries are unchanged and this is likely to be the pattern a week on Friday and how it will be reported on the BBC

2009, of course, was a high point for the Tories and a low one for Labour.

Because the Tories are defending about 70% of the seats then they’ve got so much more to lose. The current forecast is that Labour will gain 350, while the Tories will lose 310 and the Liberal Democrats 130.

So even with all of this the Tories are set to win most council seats even though LAB will have the greater national equivalent vote share.

The big question is the Ukip total.

Mike Smithson

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