FAQ

What swing do the Conservatives need to win the next election?

The short answers are:

• The Conservatives need a swing of 1.5% for Labour to lose their overall majority (equivalent to the two parties being almost exactly neck and neck in the GB vote).
• The Conservatives need a swing of 4.6% to become the largest party in the House of Commons (a lead of 6 points over Labour in the GB vote).
• The Conservatives need a swing of 7.1% to obtain an overall majority in the House of Commons (a lead of 11 points over Labour in the GB vote).

All these figures assume that the Lib Dem share of the vote remains unchanged, if the Lib Dem vote falls then the Conservatives would do slightly better, since there are more Con/LD marginals than there are Lab/LD marginals. These figures are also based on their being a uniform swing. In reality there is no such thing as a uniform swing – if the Conservatives perform better in their target seats, or if there is tactical voting against Labour, then the Conservatives could get a majority on a much lower swing.

What seat do the Conservatives need to win to get a majority?

There aren’t any particular seats the Conservatives need to win – it’s perfectly possible for them to win some seats that need large swings while failing to get more marginal seats. There is a certain symbolic importance though to the one seat that would get them a majority if they won all the seats needing a lower swing. From the 214 seats the Conservatives notionally hold on the new boundaries they would need to win an extra 112 to get the 326 seats necessary for a majority. In order of marginality, the 112th most winnable seat for the Tories is Tooting.

You’ll no doubt notice, however, that Tooting has a majority of 6.1%, while I said the Conservatives need a swing og 7.1% to get a majority. This is because many of the Conservative target seats are held by the Lib Dems or other small parties, so wouldn’t necessarily fall on a straight swing from Labour to the Tories. On a uniform swing from Labour to the Conservatives, the seat that would give the Conservatives an overall majority would be Derby North.

When do the new boundaries come into force?

The legislation introducing the boundary changes comes into force on the 27th June 2007, and the changes will apply from the next general election. Any by-elections in this Parliament will be conducted using the OLD boundaries.

Your notional figures for seat X look wrong!

Coming up with notional results for new Parliamentary boundaries isn’t an exact science. General election votes aren’t counted by electoral ward – the building blocks that make up constituencies – so actual results on the new boundaries can’t be calculated. Estimates need to be made, based on the distribution of parties’ votes within the constituencies at local elections. Of course, in some areas local election votes differ widely from national election votes, especially where there are councillors with strong personal votes or independent councillors. This leads to errors in calculating notional votes. If you are a local activist in a constituency, have canvassed wards or seen box counts then you probably have a better idea of what the effect of boundary changes in your area will be than these calculations can offer.

What about by-elections?

These are notional figures for the 2005 election, not predictions of what would happen now or in the future, so they do not take into account anything that has happened since 2005. When profiles are added to seats’ pages they will address any by-elections in the seat.

X is not MP for this constituency, their constituency has been abolished

In some cases there are errors in which MP’s details are connected to each constituency, so if any remain please do point them out. Where there are major boundary changes the MP given for a seat is the MP for the seat that I view as the predecessor seat to that. In some cases that is a debatable issue and some people may view a different seat as the predecessor, and obviously in most cases there will be parts of the seat currently represented by a different MP.

Will you be updating the results to take into account feedback or new local election results?

The notional results are how people would have voted in 2005, so using local election results from 2007 won’t be any more accurate a guide than the local election results from 2003 (which these figures are mainly based upon). The figures currently on the site are my final estimates and won’t be adjusted to take account of any more feedback – but every seat does have a comments section where people can add their own opinions on how the boundary changes might effect seats.

Seat X is actually far more winnable than seat Y

Yes, it probably is. The lists are target seats are based purely on percentage majorities, in reality the demographics of particular seats, or past tactical considerations mean that the raw figures give a misleading impression of how winnable a seat is. Some seats like Poplar and Canning Town are probably safer than the raw figures would have it appear. Others, like Bury South, seem to be Conservative targets despite the large swing required on paper. Again, every seat has a comments section where you can add your own opinions about how winnable they are.

What about Northern Ireland?

Because of the different party system, the delay to their boundary review (and because this site sprang from covering British opinion polls, which normally don’t include Northern Ireland) I have not sought to include Northern Irish seats in any of the analysis here. For all things electoral in Northern Ireland I can recommend Nicholas Whyte’s site http://www.ark.ac.uk/elections/

Are the notional figures available as a spreadsheet for download?

The full figures can be downloaded as a csv file here.

How do the figures compare to other notional figures?

There are at least two other sets of notional figures for the new boundaries. Martin Baxter has now published his own notional figures, based on slightly different formulas, at Electoral Calculus while Colin Rallings and Michael Thrashee of Plymouth University have produced figures using to a similar method to this site which will form the “official” notional figures and be used in the mainstream media. The Rallings and Thrasher figures are not available online, but there is a list of differences between the three sets of projections here

There is a mistake on the site

Any errors drop me an email or leave a comment on the page – one that is known about is that the circles around the target seat numbers will disappear if you scroll up the page on Internet Explorer 6. I’m afraid that is Internet Explorer’s fault, the site should look fine using IE7 or Firefox.

How come some people’s comments have party symbols next to them?

Registered members can chose to have their political affiliation displayed next to their comments. To register follow the link on the left-hand sidebar – registration is free and automatic, you just need to pick a name and a password.