How Britain Became a Five-Party System

For most of the post-war period, British general elections were contests between two parties, with others competing for the remainder.

That is no longer an accurate description. Five parties are currently polling above ten per cent simultaneously, and the combined share of the two traditional major parties has fallen to levels without modern precedent.

This article sets out the figures and the sequence of changes behind them.

Where the polling stands.

A seven-poll rolling average published on 24 July 2026 placed Reform UK on 24.7 per cent, Labour on 23.1 per cent, the Conservatives on 19.9 per cent, the Green Party on 12.0 per cent and the Liberal Democrats on 11.1 per cent.

Individual polls have shown variation around those figures. A poll conducted in late June placed Reform on 26 per cent, Labour on 24, the Conservatives on 18, the Greens on 13 and the Liberal Democrats on 11.

Another, published on 7 July, recorded Reform on 24 per cent, Labour on 19, the Conservatives on 18, the Greens on 16 and the Liberal Democrats on 12.

The precise ordering varies between pollsters and between weeks. The consistent feature across all of them is five parties clustered within a relatively narrow range.

The two-party share has fallen sharply.

At the 2024 general election, the Conservatives and Labour together took 57.4 per cent of the vote, which was itself the lowest combined share recorded at a general election.

By March 2026, analysis of polling by the Electoral Reform Society put the combined figure at 37.1 per cent.

That represents a fall of around twenty percentage points in under two years, and it is the single clearest measure of how the landscape has changed.

The 2024 result was already unusual.

Labour won the 2024 general election with a majority of 172 seats, taking close to two-thirds of the seats in the House of Commons.

It did so with just over a third of the votes cast. The resulting gap between vote share and seat share was the widest recorded at a British general election.

Turnout was also low by historical standards, meaning the winning party's share of the total electorate was smaller still.

The change accelerated through 2025.

Polling through 2025 recorded a series of results without precedent. Reform UK led in more polls than any other party over the year.

Labour fell below 20 per cent for the first time since the 1980s, later reaching lows around 14 per cent. Both Labour and the Conservatives polled below 20 per cent in the same poll for the first time. On three occasions, Reform recorded a higher share than Labour and the Conservatives combined.

The Green Party reached a polling high of 18 per cent during the year and moved ahead of the Liberal Democrats into fourth place in the polling averages.

By the end of 2025, five parties were consistently polling above 10 per cent.

Local elections showed the same pattern.

In the May 2025 local elections in England, Reform UK won 677 seats and took control of ten local authorities.

The May 2026 local elections produced further gains for both Reform UK and the Green Party, with Labour recording poor results across much of the country.

In the North East, Reform UK took control of Sunderland City Council. In Newcastle, an all-out election under new ward boundaries returned the Liberal Democrats as the largest group with 25 seats, with the Greens and Reform UK on 24 each and Labour reduced to two.

Support has moved in several directions.

Survey data comparing current voting intention with recorded 2024 votes shows movement between multiple parties rather than a single transfer.

One survey found 27 per cent of 2024 Conservative voters intending to vote Reform, with 66 per cent remaining with the party.

Among 2024 Labour voters, 60 per cent remained loyal, with 15 per cent intending to vote Reform, 12 per cent Liberal Democrat and 9 per cent Green.

The devolved picture differs again.

Elections to the Senedd in May 2026 were won by Plaid Cymru, which has sought to form a minority Welsh government.

Scotland, Wales and Northern Ireland each have their own party systems and, in the case of the Senedd and the Scottish Parliament, different voting systems, which produce results that do not map onto Westminster polling.

What the system produces is uncertain.

First past the post allocates seats by who wins most votes in each constituency, not by national vote share.

With five parties polling within roughly fifteen points of each other, small shifts in support can produce large and difficult-to-predict changes in seat numbers, since seats can be won on comparatively low shares of the vote.

Seat projections based on current polling vary considerably between models for that reason.

Share your thoughts.

Do you think five-party politics is a lasting change or a temporary one?