Can the decline of two-party politics be reversed?

Why electoral systems can change how much faith people have in democracy

One of four themes I’m focusing on this year is the fragmentation of British politics. There hasn’t been a poll since 3rd January in which any party reached 30%. The Conservative party is still losing votes to Reform (and has fallen into third place behind Farage’s party as I predicted in my post at the start of the year). Labour are losing votes everywhere. This isn’t just due to our current political situation but reflects the decline of big parties across the world.

Is it reverserable? Should we want to reverse it? And can electoral systems make a difference? To look at these questions we welcome back Lewis Baston, who wrote a superb guest post on the decline of the Conservatives back in July.

Lewis one of the most astute political analysts in the UK. He started out as a researcher to the great David Butler, who founded election studies in this country, and has subsequently written a number of outstanding political biographies. His most recent book “Borderlines: A History of Europe, Told From the Edges” is a fascinating guide to the way redrawn borders have changed the continent’s history.

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Can the decline of two-party politics be reversed?

Last year’s general election gave a strong parliamentary majority to Keir Starmer’s Labour on the lowest share of the vote ever for a winning party – 33.7 per cent.¹ If one accepts the logic of the First Past the Post electoral system there should be no question over the legitimacy of the outcome, but in practice the low share has had an undermining effect on the Starmer administration.

It has encouraged the opposition to regard the government as somehow illegitimate and temporary. Faith in British democracy in general has plunged – 23 per cent of people ‘almost never’ trusted governments to put the national interest ahead of party politics in 2020 but this proportion rose to 45 per cent in June 2024 on the eve of the election.

Britain is far from alone in seeing the combined share of the vote for the top two, the traditional parties of government, falling – it has happened in most of the larger parliamentary democracies, and the impact has generally been destabilising. Is there a way that we can enhance the legitimacy of majoritarian government, to future-proof it against further fragmentation? Are some electoral systems better at managing extremism and falling trust in democracy than others?

Two-party politics in decline

Let’s look first at the global pattern. The chart below is based on fourteen countries that have a parliamentary model of government, a continuous series of meaningful elections dating back to the 1950s and which are of a reasonable size. These criteria mean that it is dominated by Europe and the old Commonwealth.²

The decline in two-party politics since the post-war period has occurred across countries with different electoral systems and cultural backgrounds. In some ways the post-war years were the exception; parliamentary democracies and elections were more chaotic in the 1920s and 1930s than in the 1950s. We are reverting to a state of disorder rather than charting new territory – but the history of the interwar period makes that a warning rather than a comfort.