A re-dividing nation? A newly polarised electoral geography of Great Britain

One feature of the result of the 2015 British general election was the reduction, to a level lower than at any time since 1945, in the number of marginal constituencies. This paper shows that the main reason for this was the change in the level and pattern of support then for the country’s smaller parties, compared to the previous election in 2010. Although support for the two largest parties—Conservative and Labour—changed very little, the 2015 result nevertheless meant that each had fewer marginal seats to defend and more safe seats where its continued incumbency was virtually assured. After the 2015 election, Labour’s chances of becoming the largest, let alone the majority, party in the House of Commons were slight unless it achieves a swing of some six percentage points.