House of Commons Library

Membership of UK political parties

Published Tuesday, January 16, 2018

As of June 2017, Labour had 552,000 members and the Liberal Democrats had 102,000 members as of May 2017. As of August 2017 the SNP had 118,000 members. As of December 2016 the Green Party (England and Wales) had 46,000 and UKIP 34,000. As of December 2013 (latest published figure) the Conservative Party had 149,800 members. Party membership has risen notably since 2013, both in total and as a percentage of the electorate.

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Analysing party membership data

Comparing party membership between political parties can sometimes be difficult. Political parties are under no legal obligation to publish membership statistics. There's also no uniformly recognised definition of membership, nor is there an established method or body to monitor it. Nonetheless, the majority of main parties voluntarily include membership figures in annual accounts for the year ending 31 December, submitted to the Electoral Commission.

Although all parties are required to submit these annual accounts by the Political Parties, Elections and Referendums Act (2000), they're not obliged to include membership data. When annual accounts do include these figures, they’re probably the most reliable estimates available.

Data published by the Electoral Commission

According to the latest accounts released by the Electoral Commission, on 31 December 2016:

  • The Labour Party had around 544,000 members, an increase from 388,000 in December 2015
  • The Scottish National Party had around 119,000 members, an increase from 115,000 in December 2015
  • The Liberal Democrat Party had around 78,000 members, a rise from 61,000 in December 2015
  • The Green Party (England and Wales) had around 46,000 members, a decrease from over 63,000 in 2015
  • UKIP had around 34,000 members, a decrease from over 40,000 reported in December 2015
  • The Conservative Party does not publish data on party membership in it’s annual accounts

Latest available data

Aside from the Electoral Commission publication, more up-to-date information on party membership is sometimes available from parties themselves or other sources. The latest available estimates from political parties’ head offices, press releases and the suggest that:

Party membership as share of electorate

Membership of the Conservative, Labour and Liberal Democrat Parties has increased to around 1.7% of the electorate in 2017, compared to a historic low of 0.8% in 2013. Across the UK, Labour Party membership increased from 0.6% in 2013 to 1.2% in 2017.

Further analysis of membership of UK political parties will be available in the House of Commons Library Briefing which will be published soon.

About this briefing

This note uses a range of sources to examine party membership and support in the UK, specifically membership levels, the income membership fees generate and the social characteristics of party members. For context, it also provides data on membership of non-party political organisations including trade unions, charities and campaigns.

Historic analysis of Labour, Conservative and Liberal Democrat parties membership is available in the section 2.2 (pages 6-8)

Analysis of party membership since 2002 is available in the section 2.4 (pages 9-13)

Figure 2 (on page 8) illustrates data on party membership as percentage electorate from 1970 - 2017

Section 4 (on pages 17-20) provides detailed analysis of social characteristics of party members and supporters.

Section 5 (on pages 21-24) analyses non-party political activity and engagement.

Section 2.1 (on page 5) provides information about data sources used to produce this paper.

Commons Briefing papers SN05125

Authors: Richard Keen; Lydia Jackson

Topic: Political parties

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