Skip to main content
School of Politics and International Relations

Who joins a political party and why?

Whitehall sign

An intensive three-year project led by Professor of Politics Tim Bale has led to deeper understanding of political party membership in Britain. Who joins or leaves a political party and why? What do parties think of their members and how does this impact their policies? And how does all of this play out in the media?

The Party Members Project (PMP) was a project to study the membership of the six largest political parties in the UK: the Conservatives, Labour, the SNP, the Liberal Democrats, the Greens, and UKIP. The PMP collected original quantitative and qualitative data on both party members and the parties themselves.

The project has enabled a more accurate representation of the opinions and the demographics of party members. Bale’s research has examined party members’ views on key social and political issues, as well as their opinion on the record and conduct of their leaderships. 

As a result, the political parties themselves have gained a deeper understanding of their membership, learning who joins their party, who leaves and what makes them do so. The project’s data and analyses have undoubtedly taught parties more about their members. 

The PMP’s research has had an impact on the media too, ensuring that political journalists know more than they did before about the realities of political party membership.

A window on a tumultuous political period

Bale’s research was developed with Paul Webb (Sussex) and Monica Poletti (Queen Mary) and funded by the Economic and Social Research Council (ESRC). The project has coincided with a dramatic period of upheaval in British politics, during which members played a big role – not least because they were called on several times to elect our parties’ leaders, including Prime Minister Boris Johnson. The PMP initially ran from 2015-18 before continuing, with a second extension of ESRC funding, into 2019-2020 to cover the 2019 general election.

The project’s ground-breaking work used web-based survey research that ran independently of the parties it looked at. 

Key issues explored by the PMP included:

  • the characteristics of party members
  • why people join and leave parties
  • what members do during election campaigns
  • members’ ideological and policy views
  • the extent of Islamophobia and anti-Semitism 

In addition, Bale and colleagues also conducted interviews with party staffers and politicians. The 2015 surveys were supplemented by voter surveys of partisans who were not party members, as well as surveys of members of unions affiliated to the Labour Party. 

Some of the findings confirmed commonly held views, but the research revealed some surprises.

The characteristics of party members

  • Conservative Party members were found to be overwhelmingly male (70/30)
  • Labour Party members were much more middle-aged and more middle-class than some might have expected
  • Britain's party members do not reflect its ethnic diversity: they are overwhelmingly white

Why people join and leave parties

  • People join parties primarily for ideological, although a feeling of belonging and (for some) career ambitions matter too
  • Political parties lose as well as gain lots of members. People most often leave because they disagree with the ideological direction their leaders are pursuing

What members do during election campaigns

  • Variation between parties aside, only a very small proportion of members do that much campaigning.
  • Members will often participate in on-the-ground activism because they feel part of the local party’s social network
  • Many non-member supporters also campaign. They may be persuaded to join if parties cleared up misperceptions about the commitment involved 

Members’ views on Brexit

  • Members’ views on Brexit often differed sharply from their parties’ votes and their parties’ official policies
  • Conservative members became increasingly keen on a hard or no-deal Brexit 
  • Labour members were overwhelmingly and intensely pro-Remain and favoured a Second Referendum
  • These changing views contributed hugely to both Johnson’s and Starmer’s successful leadership bids

The extent of Islamophobia and anti-Semitism 

Anti-Semitism, and the dismissal of such in the Labour Party was a serious problem, as was Islamophobia in the Conservative Party.

How has PMP’s research affected media reporting and public perception?

By providing strong empirical evidence. Bale’s research has directly affected how key commentators and journalists in the national and international news media report on British political party membership. This has hopefully led to shifts in public perception. PMP’s findings have been widely reported in mainstream and alternative media sources across the political spectrum.  

PMP’s findings about the demographics of Labour Party members helped to explain and even predict Corbyn’s re-election as party leader in 2016.

[PMP] has proved to be a highly valuable resource for engaging storytelling. It’s offered audiences a unique insight into attitudes toward party membership...This has been especially important in providing greater context and understanding to the leadership victor[y] of Jeremy Corbyn.
— Tom Edgington, Senior Broadcast Journalist for BBC News

Similarly, the project’s findings about the socially conservative demographics of Conservative Party members helped to explain and even predict Johnson’s election in 2019.

When the Project's research revealed that Conservative grassroots members rejected Theresa May’s ‘Chequers’ Brexit deal, preferring to run the gauntlet of no deal. It was that tide of opinion that eventually propelled Boris Johnson to the premiership.
— Heather Stewart, Political Editor of the Guardian

The project showed that anti-Semitism within the Labour Party – at the grassroots level – was a real issue. Similarly, they discovered historic Islamophobic prejudice among a substantial minority of Conservative Party members.

[The PMP] has given me real data rather than anecdotal observations on the extent of Islamophobia on the right and anti-Semitism on the left. At a time when party members have so much power over MPs and leaders, it provides an anchor in fact for anyone discussing Westminster politics.
— Nick Cohen, the Observer

Based on the evidence and its reach, the project’s extensive media engagement has thus shaped and advanced public understanding. 

Informing the way political parties interact with their members

Bale’s research has informed how political parties understand their membership, and how they might best engage with them. The project team gave face-to-face briefings and presentations to four of the six parties surveyed: Labour, the Conservatives, the Lib Dems and the Greens.