Party system fragmentation and single-party government: the British general election of 2015

Abstract:

The 2015 British general election returned a majority Conservative government after five years of coalition government – the first coalition government in Britain since 1945. For other recent contributions in the elections in context series, see for example André and Depauw (2015), Aylott and Bolin (2015), Arter (2015), Faas (2015), and Haugsgjerd Allern and Karlsen (2014).

The result defied expectations of another hung parliament, with Labour as the largest party. It could, perhaps, be seen as a return to ‘business as usual’ under Britain’s majoritarian electoral system. But the result conceals one of the most tumultuous elections in recent British history. Support for the Liberal Democrats – which had consistently been the ‘third force’ in British politics – collapsed dramatically, resulting in the loss of 49 out of 57 MPs. The Scottish National Party (SNP) swept to dominance in Scotland, winning 56 out of 59 seats. The United Kingdom Independence Party (UKIP) emerged as an important electoral force, winning the third highest share of the vote, although it was unable to translate this into MPs, winning only one seat. The sum of these changes was the most volatile election since 1931 (as measured by the Pedersen index) and the highest effective number of electoral parties since expansion of the franchise in 1918. The Labour party’s response to defeat was, via its membership election system, a strongly left-wing leader, Jeremy Corbyn. This, with the forthcoming referendum on Britain’s membership of the European Union, offers further potential for on-going upheaval in British politics.