How UK Elections Work: First Past the Post Explained

Every few years, British voters go to the polls to elect their Member of Parliament. The candidate with the most votes wins. It sounds simple, and in one sense it is. But the UK's electoral system — first past the post — produces results that can look deeply unfair, with parties winning large majorities in Parliament on less than 40% of the national vote, and millions of votes cast for losing candidates effectively discarded. Here is how the system works, why it persists, and what the alternatives might look like.

First Past the Post: The Basics

In a UK general election, the country is divided into 650 constituencies (also called seats). Each constituency elects one Member of Parliament (MP). Voters mark an X next to one candidate's name. The candidate with the most votes wins, regardless of whether they secure an absolute majority.

This is first past the post (FPTP), sometimes called a plurality system or winner-takes-all. If Candidate A gets 18,000 votes, Candidate B gets 17,500, and Candidate C gets 10,000, Candidate A wins the seat. The 27,500 votes for B and C count for nothing in terms of parliamentary representation.

There is no second round, no preference voting, no proportionality. Whoever comes first wins. Everyone else loses.

How It Shapes Election Results

FPTP has a powerful effect on the composition of Parliament. Because only the winner in each seat matters, the system tends to:

1. Over-reward the largest party

A party that wins, say, 40% of the national vote can easily win 50% or more of the seats if its support is efficiently distributed. This is because FPTP rewards parties whose votes are concentrated in winnable seats, not spread thinly across the country.

In the 2019 general election, the Conservative Party won 43.6% of the vote but 56.2% of the seats — a majority of 80. Labour won 32.1% of the vote but only 31.1% of the seats. The system amplified the Conservatives' lead and delivered a landslide.

2. Punish smaller parties with dispersed support

Parties whose support is spread evenly across the country, rather than concentrated in specific regions, win far fewer seats than their vote share suggests. The Liberal Democrats won 11.6% of the vote in 2019 but only 1.7% of the seats (11 out of 650). The Green Party won 2.7% of the vote and one seat.

By contrast, the Scottish National Party (SNP) won 3.9% of the national vote — less than the Greens and a third of the Lib Dems — but won 48 seats, because its support is concentrated in Scotland.

3. Create 'safe seats' and 'swing seats'

Most constituencies are safe seats, where one party has such a strong lead that the result is never in doubt. In these seats, opposition voters know their vote will not change the outcome, which can depress turnout and reduce accountability.

Elections are decided in a small number of marginal or swing seats where the result is close. Parties focus their campaigns, resources, and policy promises on these seats, effectively ignoring the rest of the country.

According to the Electoral Reform Society, fewer than 10% of UK constituencies are genuinely competitive. The other 90% are decided before the campaign begins.

The Case for First Past the Post

Despite its distortions, FPTP has defenders. The arguments in its favour are:

Strong, stable government

FPTP tends to produce single-party majority governments, which can pass their manifesto into law without needing to negotiate with coalition partners. Supporters argue this gives voters a clear choice and delivers decisive government.

A direct link between voters and MPs

Every constituency has one MP, and voters know exactly who represents them. This creates a clear line of accountability. If your MP fails to deliver, you can vote them out.

Simplicity

FPTP is easy to understand and quick to count. Voters mark one X, and the results are usually known within hours. More complex systems (like the single transferable vote or party-list PR) can take days to count and require voters to rank candidates or understand party lists.

Keeps extremists out

Because FPTP rewards parties with broad, concentrated support, it makes it harder for fringe or extremist parties to win seats. A party with 5% of the vote spread across the country wins nothing. In a proportional system, that same 5% might win 30 seats.

The Case Against First Past the Post

Critics argue that FPTP is fundamentally undemocratic. The objections are:

Votes are wasted

In 2019, 22 million votes — nearly half of all votes cast — were for losing candidates and had no effect on the composition of Parliament. In a safe seat, a vote for anyone other than the incumbent is effectively discarded.

Disproportionate results

A party can win a majority of seats with a minority of votes. In 2005, Labour won 55% of the seats on 35.2% of the vote — the lowest vote share for a majority government in modern history. The system does not reflect the will of the electorate.

Tactical voting

Because only the winner matters, voters in marginal seats often vote not for their preferred candidate but for the least-bad option with a chance of winning. This distorts the true level of support for parties and policies.

Regional imbalance

FPTP can lock parties out of entire regions. In 2019, the Conservatives won no seats in several major cities despite winning millions of votes there. Labour won no seats in large parts of southern England. This creates a Parliament that looks more divided than the country actually is.

The Alternatives: Proportional Representation

Most democracies do not use FPTP. They use some form of proportional representation (PR), where parties win seats in proportion to their share of the vote. The UK already uses PR for some elections:

• Scotland and Wales use the Additional Member System (AMS) for their devolved parliaments, combining constituency MPs with regional top-up seats to make the result more proportional.
• Northern Ireland uses the Single Transferable Vote (STV) for its Assembly, where voters rank candidates and seats are allocated proportionally.
• European Parliament elections (until Brexit) used a party-list system.

How PR would change UK elections

If the 2019 general election had been run under pure PR, the result would have looked very different:

No party would have had a majority. The Conservatives would have needed to form a coalition or govern as a minority.

The trade-off

PR produces parliaments that better reflect how people voted, but it also makes single-party majority government much rarer. Most PR countries have coalition governments, which require parties to negotiate and compromise. Supporters say this forces consensus and moderation. Critics say it gives disproportionate power to small parties and makes it harder to deliver clear manifesto promises.

Why Reform Has Not Happened

Despite decades of campaigning, the UK has not switched to PR for Westminster elections. The reasons are:

1. The two big parties benefit from FPTP and have little incentive to change it.
2. The 2011 referendum on the Alternative Vote (AV) — a modest reform, not full PR — was rejected by 68% of voters.
3. Tradition and inertia — FPTP has been used since the 19th century, and many voters are suspicious of change.
4. Fear of coalition government — The 2010–2015 Conservative-Lib Dem coalition was unpopular, and opponents of PR argue it would make coalitions the norm.

The Bottom Line

The UK uses first past the post to elect MPs, a system in which the candidate with the most votes in each constituency wins, even without a majority. FPTP tends to produce single-party governments and a direct link between voters and MPs, but it also produces disproportionate results, wastes millions of votes, and punishes smaller parties with dispersed support. Proportional representation would make Parliament more representative but would likely require coalition governments. The system persists because the two main parties benefit from it, and voters rejected even modest reform in 2011. Whether FPTP is democratic or deeply flawed depends on whether you value stable government or fair representation more.