Two-Party to Multi-Party Politics - Vernon Bogdanor

The Postwar Two-Party System Was an Exceptional Period

Vernon Bogdanor argues that Britain’s familiar two-party model—Conservatives versus Labour—was unusually dominant between 1945 and the early 1970s, rather than the country’s permanent political norm.

Support for the two main parties averaged about 90% in the seven elections from 1945 to 1970, reaching roughly 97% in 1951. From 1974 to 2017, their average combined support was about 74%.

The 2017 election appeared to reverse this trend: 84% of voters backed the Conservatives or Labour, the highest combined share since 1970. Bogdanor cautions that one election, particularly one shaped by Brexit, cannot establish that Britain has returned to a two-party system.

Why the Postwar System Was Stable

Bogdanor identifies several conditions that reinforced two-party politics:

• Class-based voting: Working-class voters tended to support Labour, while middle-class voters strongly favoured the Conservatives. These loyalties changed slowly, limiting electoral volatility.
• A shared political framework: Despite disputes over the distribution of wealth, both parties broadly accepted the postwar mixed economy, welfare state and goal of full employment. Their differences could be negotiated through policy concessions.
• A sense of national cohesion: Most voters saw themselves as part of one political community. Northern Ireland was a major exception, where politics was more strongly shaped by national and religious identity.
• A floating centre: Moderate voters—especially skilled working-class voters—could switch between the parties, giving each party an incentive to appeal to them with moderate policies.
• First-past-the-post (FPTP): The electoral system made it difficult for smaller parties to win representation, encouraging people to work within one of the two established parties instead.

What Weakened the Two-Party Pattern

• Class loyalties loosened: Social identities became more varied, and fewer voters felt bound to vote as their families had voted. This increased switching between parties.
• The UK became more politically divided by region: England, Scotland, Wales and Northern Ireland developed distinct party contests and priorities. In 2017, a different party won in each of the four nations.
• Identity gained importance: In elections such as those of 2015 and 2017, questions of national identity and belonging—especially whether voters felt British, English, Scottish or European—could matter more than traditional arguments about taxation, state ownership and income distribution.
• Confidence in governments’ ability to solve problems declined: The 1974 “Who governs?” election, called during conflict between Edward Heath’s government and the trade unions, was an early sign that voters were less certain either major party could resolve national problems.
• The postwar consensus broke down: Margaret Thatcher and Tony Blair established a later consensus around market liberalism and a more limited role for the state. Bogdanor argues that the 2008 financial crisis undermined this consensus, and that in 2017 both major parties distanced themselves from it.
• Proportional representation (PR) expanded in other elections: PR for devolved bodies, local authorities, the London Assembly and European Parliament elections made voting for smaller parties more familiar. The success of parties such as the SNP and UKIP also showed that smaller parties could attract substantial support, even when FPTP limited their seats in Westminster.

The 2017 Election: A Two-Party Revival, but Not Necessarily a Lasting One

Brexit dominated the campaign. More than one-third of respondents in the British Election Study cited it as the country’s most important issue.

The referendum reshaped party support: many Leave voters moved from UKIP to the Conservatives, while Labour attracted many Remain voters, including voters who had previously supported the Greens and Liberal Democrats.

Brexit also disrupted traditional class voting. Labour gained support in some affluent areas and university towns, while the Conservatives did well in several post-industrial constituencies.

Age and education were also associated with voting patterns: younger voters and graduates were more likely to support Labour, while older voters and those without formal qualifications were more likely to support the Conservatives.

Bogdanor therefore treats 2017 as a possible Brexit-specific polarisation, not conclusive evidence that multi-party politics had ended. Brexit might continue to reshape party competition, or the 2017 result might prove an exception.

Why Hung Parliaments May Become More Common

The presence of more third-party MPs makes it harder for either major party to secure an overall majority. In 2017, parties other than the Conservatives and Labour held 70 of the 650 seats.

The number of marginal seats has fallen substantially. Using John Curtice and Michael Steed’s definition, there were 166 marginal Conservative–Labour seats in 1955 but only 89 in 2017. With fewer seats that can change hands, a party may need a larger lead to win a working majority.

These changes suggest that the hung parliaments of 2010 and 2017 may not have been accidental. FPTP is often defended as a way to produce strong, single-party government, but Bogdanor questions whether it can reliably do so under current conditions.

He also challenges the idea that single-party majority government was always Britain’s norm. Before 1945, coalition and minority governments were common, and the country had periods of multi-party competition. The postwar decades may therefore be the historical exception.

A Warning Against Political Prediction

Bogdanor concludes that electoral trends and political “laws” should be treated cautiously. The 2017 result confounded expectations about youth participation, campaign importance, the centre ground, economic competence, leadership, class voting and the apparent decline of the two-party system.

Polls provide a snapshot rather than a dependable forecast, and political outcomes depend on campaigns, issues and voters’ choices. Politics, he argues, cannot be treated as a reliably predictive science; historical analysis can provide perspective, but it cannot eliminate surprise.

Speakers and Sources Featured

• Speaker: Vernon Bogdanor.
• Named sources and commentators cited: W. S. Gilbert and Arthur Sullivan (including the song from Iolanthe); George Orwell; Karl Marx; Ernest Bevin; David Butler and Robert McKenzie (in connection with the election-night swingometer); John Curtice and Michael Steed; Will Jennings and Gerry Stoker; Harold Macmillan; A. J. P. Taylor; Humphrey Lyttelton; and Isaiah Berlin.
• Other sources mentioned: The British Election Study; an unnamed journalist writing for The Economist.
• Political figures discussed as examples: Winston Churchill, Clement Attlee, Harold Macmillan, Harold Wilson, Edward Heath, Margaret Thatcher, Tony Blair, Gordon Brown, David Cameron, Theresa May, Jeremy Corbyn, Nigel Farage and Ruth Davidson.