How does first past the post work?
One MP per constituency, most votes wins, no prizes for second. Simple to vote in — and, in a five-party era, capable of producing the most distorted results in British history.
The mechanics
The UK is divided into 650 constituencies of roughly 70,000 electors. On polling day you mark one X for one candidate; whoever gets the most votes in your constituency becomes its MP — 35% is enough if the rest is split. National vote share is never counted for anything: a party's power is purely the sum of local wins.
What the system does to a five-party country
FPTP rewards geographically concentrated support and punishes evenly spread support. In 2024 that produced the most disproportionate result in modern history: Labour took 63% of seats on 33.7% of votes, while Reform's 14% earned five seats and the Greens' 7% earned four. With today's polling even more fragmented, the distortions could go any direction — a party on 26% could win a near-majority or underperform badly depending entirely on how its vote clusters. It's why seat projections diverge so wildly from vote shares, and why a hung parliament is a live scenario.
The reform argument
The Lib Dems and Greens (and, since 2024, Reform) advocate proportional representation — their voters are the system's biggest losers. Labour and the Conservatives, the system's historical beneficiaries, defend the constituency link and decisive outcomes. In any hung parliament, electoral reform is likely to be on the negotiating table for the first time since 2011.
Frequently asked questions
How does first past the post work?
Each of 650 constituencies elects one MP — the candidate with the most votes locally wins, even without a majority. National vote share plays no role: a government is whoever's local wins add up to a Commons majority.
Why is first past the post controversial?
Because seats and votes can diverge wildly: in 2024 Labour won 63% of seats on under 34% of the vote, while 21% of voters (Reform + Green) got nine seats between them. Supporters counter that it keeps a local MP link and usually produces decisive governments.
Could the UK change its voting system?
Only via legislation, and realistically only if a hung parliament makes reform the price of a coalition — as nearly happened in 2010. The 2011 AV referendum rejected one alternative, but polling since shows growing support for proportional systems.