Two big parties, or many?
The nutshell
The UK has many political parties. Two are usually the biggest — Labour and the Conservatives. One of these two has formed nearly every UK government since the Second World War, but smaller parties still win seats in Parliament.
Every fact on this page comes from official records and non-partisan fact-checks. Each source tag — like Parl — opens where a fact comes from.
The basics
Two parties usually lead
Since the Second World War, all but one UK government has been formed by Labour or the Conservatives. The party with the most MPs after a general election normally forms the government, and the next-largest party becomes the official Opposition.Parl
But many parties win seats
Parliament has 650 MPs, and MPs come from many parties. At the 2024 general election Labour won 411 seats, the Conservatives 121 and the Liberal Democrats 72. The SNP, Reform UK, the Green Party, Plaid Cymru and several Northern Ireland parties also won seats.HoC
Fewer votes for the big two
In 2024 Labour and the Conservatives together won about 58% of the vote. Other parties and independents won the other 42%.FF More voters backed smaller parties than at most past elections.
Two-party, or multi-party?
The UK is often called a two-party system because two parties usually take turns in government. The Institute for Government argues that multi-party politics is becoming a settled part of UK democracy.IfG
- Two large parties usually means one wins enough seats to govern alone, without needing a coalition
- A clear contest between two main parties makes it simple to see which party would form the next government
- A governing party can be judged on its whole record and voted out as one at the next election
- Smaller parties can win many votes across the UK but only a few seats in Parliament
- A vote for a party that rarely wins a local seat can feel like it changes nothing
- A system led by two big parties can leave some views with little voice in the House of Commons
The deep end6 min
How votes become seats
The UK is split into 650 areas called constituencies. Each area elects one MP, and the candidate with the most votes in that area wins the seat. This system is called first past the post. The party that wins the most seats usually forms the government, and its leader becomes Prime Minister.Parl A party can win a large majority of seats without winning half of all the votes cast.
Many parties, few big winners
At the 2024 general election, MPs were elected from Labour, the Conservatives, the Liberal Democrats, the SNP, Reform UK, the Green Party, Plaid Cymru and several Northern Ireland parties.HoC First past the post rewards a party whose votes are packed into local areas. Full Fact records that Labour won about 63% of the seats from 33.7% of the vote, while Reform UK won about 14% of the vote but only about 1% of the seats.FF
What each side argues
Supporters of first past the post, including successive governments that have kept it for Westminster, argue that it usually produces a clear single-party majority and avoids the need for a coalition — two or more parties governing together.Parl The Institute for Government argues that the rise of smaller parties means multi-party politics is becoming a settled feature of UK democracy, and that Parliament will increasingly need to cope with minority governments and coalitions.IfG
How settled the picture is
The seat counts and vote shares above are official results and are not in dispute.HoC Whether a two-party or a multi-party system serves the UK better is a contested question, and each answer is a position held by named groups rather than a settled fact. The topics on what a political party is and what a manifesto is look at how those parties are built.