Is Two-Party Politics Really Dead In The UK?

By Simon Wren-Lewis, April 22, 2025

Simon Wren-Lewis is Emeritus Professor of Economics and Fellow of Merton College, University of Oxford. He Was One of the Seven Members of the UK Labour Party’s 2015-2016 Economic Advisory Committee.

Rob Ford, previewing the upcoming election on 1st May in the Guardian, emphasises how the Liberal Democrats, Greens and Reform are likely to make big gains. Going further, in a recent article in Prospect, Peter Kellner suggests the domination of Labour and Conservatives, even in general elections where the First Past The Post (FPTP) voting system gives them a huge advantage, is over for good. I started out being more sceptical, but as I’m an amateur on these matters, I thought it was worth discussing in more depth.

The key evidence in favour of the view that multiparty politics in the UK [1] is here to stay is the trend in vote shares since shortly after WWII. Here is a more complete version of the numbers that Kellner gives in his article.

Since 1951, the UK vote share of Labour and the Conservatives combined has fallen from nearly 90% to below 60% in 2024. However the last observation is important. Kellner argues, convincingly in my view, that 2017 and 2019 are outliers because Brexit polarised politics, and so 2024 represents a return to a falling trend for the two main party’s vote share. But is this really a trend or a series of step changes due to clearly defined political developments?

Until 2010, the fall in the Lab+Con share was largely about a rising share for the Liberals/SDP-Liberal Alliance/Liberal Democrats, and here there is a clear step change around the 1970s. From 1945 to 1970 the Liberal vote share oscillated just below 10%, but from 1974 to 2010 it averaged around 20%. The rise in nationalist parties in Scotland and Wales plus the rise in UKIP in the 2000s (to achieve a 3% vote share in 2010) has a more modest influence over this period. In 2015 the LibDem vote collapsed, but the UKIP vote, and to a lesser extent the Green party vote, rose to almost compensate. Even if we discount 2017 and 2019 as Kellner suggests, 2024 looks like another step change, with the combined vote share of Reform, LibDems and the Greens being 33%.

The argument I want to present is that these two step changes occurred when the two major parties moved away from being close to where the average voter is. To understand more recent movements, we need to look at policy space in two rather than one dimension.

In the diagram above, the centre is where the average voter is, which may change over time as voter opinion changes. From 1945 to 1970, both parties were close to the centre of electoral opinion, with Labour being a little more left wing and socially liberal, the Conservatives more right wing and socially conservative. [2] Most of the political action was about economics, and voting was largely class based. FPTP ensured that there was little scope for other parties to gain a substantial vote share.

The 1970s brought inflation and industrial unrest, and I would suggest as a result public opinion moved away from both the union movement and a Labour party using incomes policies to reduce inflation. In terms of the diagram above, Labour shifted left because its policies didn’t shift with public opinion. This produced a step increase in the Liberal vote in 1974. The Conservatives in the 1970s (particularly after Thatcher became leader) moved right in economic terms, a move that in 1979 went well beyond public opinion and so they moved to the right in the diagram above. The gap between Labour and the Tories in economic terms was greatest in 1983, when the Labour vote share collapsed and the SDP-Liberal Alliance won almost as big a vote share as Labour. After 1983 Labour gradually moved back towards the economic centre ground, and won power again in 1997.

At this point the Conservatives were now much further away from the centre ground than Labour on economic issues, and as a result they began to campaign much more on social issues, and immigration in particular. Voting became less class based, and more age based (because older voters tend to be more socially conservative). This may have allowed the Conservatives to make inroads into traditionally Labour working class areas, but initially at least economic interests meant that their socially conservative rhetoric was not matched by actions. This led to the emergence of a populist right wing party, UKIP, that started to gain a significant vote share.

Skip to 2024, and Labour moved to adopt some moderately socially conservative policy positions, and also implicitly a more right wing policy in terms of public service provision. The Conservatives, in an attempt to counter the threat from Farage, adopted even tougher socially conservative policies (principally Brexit) and became increasingly populist in nature. This had two effects. The first, relatively minor, was to give the Green party its highest national vote share at 6.4%. The second, and perhaps more important, was to give the socially liberal LibDems their highest seat total since WWII.

For power, under FPTP, seats count for everything and vote share nothing. If the Conservatives stay as they are, which is a populist party advocating pretty extreme socially conservative views from a populist perspective, this leaves socially liberal but economically right wing voters very reluctant to vote for them. The Liberal Democrats in 2024 succeeded in capturing many of these votes, and as a result they obtained their highest seat total since WWII with a much lower vote share than most of the 1974-2010 period.

Seen in this way, the 2024 General Election was not the latest point on some inevitable trend to multi-party politics, but the result of shifts in the policy stance of the two main parties. Essentially the Conservatives first moved to neoliberalism, and then to right wing populism, and now Labour has moved in that direction leaving a large part of policy space empty for other parties to fill. As a consequence, whether this situation persists or becomes more marked will depend on whether the two main parties stay where they currently are, or whether they move back to where they once were.

If the Conservatives continue to focus on competing with Farage, then the LibDems have a good chance of keeping their high seat total, but their scope for further growth is modest as they were last year second in only 27 seats. [4] Otherwise the main beneficiary of this Reform/Tory battle is Labour. If Labour stay where they currently are, the Green party is second to Labour in 39 seats and therefore has scope to increase both its vote and seat total. [3] If Farage can be persuaded into an electoral pact or (less likely) the Conservatives collapse, we could get the neat result that the UK becomes a four party system, with each party representing one of the quadrants in the diagram above.

However it is equally possible that 2024 represents a low point for the two main parties. Labour could, if only for purely electoral reasons, shift back towards a moderately socially liberal position while at the same time increasing taxes further to fund better public services, as they did in the early 2000s. The Conservatives, under a new leader, could focus more on winning back the Liberal Democrat rather than Reform vote. In those circumstances Labour could use the prospect of a return of a Tory government to squeeze the Green vote, with the Conservatives using the same tactics to squeeze both the LibDems and Reform.

Both scenarios are possible. In particular, with less tactical voting in Council elections and more protest voting, the pressure on the two main political parties to change their policy positions and tactics before the next General Election will be intense. What is clear, if this analysis is right, is that any continuing decline or resurgence in the fortunes of the two main parties lies largely in their own hands.

Footnotes

[1] Multi-party politics has of course been with us for some time in Scotland, Wales and Northern Ireland, so this is really a question about England.

[2] In this diagram the centre is the average of voter opinion, which in terms of policy positions may shift over time. For example, since WWII voters have been becoming much more socially liberal. Undoubtedly opinion did shift left in 1945, which was why Labour’s radical policy agenda was able to win that election, and Conservative policy did then shift left to reflect that.

[3] Competition from existing or new left wing parties would of course hinder this.

[4] The main danger for the LibDems is if Labour become very unpopular among economically right wing voters, and the Conservatives successfully argue that the LibDems would support a minority Labour government. 

- - - - - - -