The UK Election - Battleground Map

The Daily Telegraph has released a Google Map of the marginal seats in the UK election. The Telegraph's map divides the country into safe constituencies (seats that are likely to vote for the incumbent political party in the seat) and marginal constituencies (seats that might change hands).

Unfortunately The Telegraph has not explained the methodology they used (they say the map is based on Research by the Electoral Reform Society) to determine which are safe seats and which are marginals. The accompanying article mentions seats which have a long history of voting for a particular political party but I would be surprised if that is the criteria they used for determining marginal seats.

The map must be based either on opinion polls or on the votes cast in the 2010 general election (or on some combination of the two). My guess is that it is based on opinion polls, which is why Labour seats in Scotland and Liberal Democrat seats in the South West are being shown as marginal on the map (many of these seats wouldn't be marginal based on the 2010 election). In either case the Electoral Reform Party has to have made an arbitrary judgement call as to what point a seat swings from being a safe seat to being a marginal (there have been some big outliers in recent polls so it would be useful to know which polls have been used as well).

However the map is still useful as a general guide to which UK seats are most likely to determine the outcome of the UK general election in three weeks time. The large number of seats in Scotland (many of which look likely moving from Labour to SNP) and in the South West (some of which look like moving from Lib Dem to Conservative) are likely to have a big impact on the UK election and what look like being interesting discussions after the election about which political parties will form a coalition.

Via: Visual Loop - Digital Cartography (93)