What Is a Political Party? What Parties Do and How UK Rules Work

A political party is an organisation of people who share broad political aims and work together to win elections and hold power. A party puts forward candidates under a shared name, offers voters a programme of what it would do in office, and, once elected, organises its members in parliament into a government or an opposition.

Some historians trace the first modern parties to Britain in the late 17th century, when the Whigs and the Tories formed around opposing views of royal power: the Whigs backed a Protestant constitutional monarchy, the Tories a strong monarchy.

What political parties do

Select candidates

Parties decide who stands under their name. Instead of judging hundreds of unknown individuals, voters can use the party label as a guide to what a candidate broadly stands for. In the UK, each registered party has a nominating officer who is responsible for its arrangements for submitting candidates and for approving the descriptions and emblems they use on ballot papers.

Offer programmes

Parties draw up policies and present them to voters, at UK general elections usually in a manifesto. A party's broad identity also sends a signal about the kinds of policies it might pursue if it won power.

Organise government and opposition

In a parliamentary system, the party or parties that can command a majority form the government. In Westminster systems the largest party outside government forms the Official Opposition, which scrutinises ministers and presents itself as an alternative government.

Involve citizens

Parties recruit members, mobilise voters at elections and, in many cases, give members a say in choosing the party leader. Membership often involves paying dues and agreeing not to join a rival party, and sometimes accepting the party's aims.

How parties are regulated in the UK

The main law is the Political Parties, Elections and Referendums Act 2000 (PPERA), which received Royal Assent on 30 November 2000. It set up the Electoral Commission, the independent body that regulates parties and their finances. See what an electoral commission does for its wider role.

Area	What PPERA requires
Registration	A party must be on the Commission's register for Great Britain or for Northern Ireland to field candidates under its name. Unregistered candidates may be described only as "Independent" or given no description.
Officers	Every registered party must have a registered leader, nominating officer and treasurer. The leader may also hold one or both of the other posts.
Financial scheme	A party cannot be registered until it has adopted a scheme, approved by the Commission, for managing its finances.
Donations	Donations over £500 may be accepted only from "permissible donors", such as individuals on a UK electoral register, UK-registered companies carrying on business in the UK, registered parties and trade unions. The Act also bars donations from foreign and anonymous sources.
Reporting	The party treasurer reports donations every quarter. Since 1 January 2024, a donation over £11,180 to a party's central organisation must be reported.
Accounts and spending	Parties must submit regular statements of accounts, and their spending on election campaigns is capped.

The step-by-step process for registering a new party is covered in how to start a political party in the UK.

How UK parties are funded

UK parties raise money from their own supporters, and some public money is also available for specific purposes.

• Membership fees. Each party sets its own subscription rates.
• Donations and loans. These come from individuals, companies, trade unions and other permissible donors, under the PPERA rules above.
• Short money. Opposition parties in the House of Commons receive an annual payment to help with their parliamentary work, travel and the running of the Leader of the Opposition's office. A party qualifies if it won at least two seats at the last general election, or one seat and more than 150,000 votes, and its MPs have taken the oath. It is named after Edward Short, the Leader of the House who proposed it in the 1970s.
• Policy development grants. Under section 12 of PPERA, the Electoral Commission can make grants to help parties with at least two sitting MPs develop policy for their manifestos, up to a total of £2 million a year.

How much public money parties should receive is itself debated. Supporters of more state funding argue it would reduce reliance on large donors; opponents argue taxpayers should not have to fund parties they disagree with, and that parties should earn their income from supporters.

Party systems

A party system describes how many parties compete seriously for power and how they relate to each other. The usual classification has four types.

• One-party system. A single party has the exclusive right to form the government and sole control of political power.
• Dominant-party system. Elections are competitive and other parties exist, but one party wins time after time and its defeat seems unlikely in the foreseeable future.
• Two-party system. Only two parties, or alliances, have a realistic chance of forming a majority, even if smaller parties also win seats. The United States and the United Kingdom are often given as examples.
• Multi-party system. Several parties are capable of winning office, and governments are often coalitions.

The voting system helps shape which type develops. Single-member seats decided by plurality, as in first past the post, tend to favour competition between two main parties, a pattern known as Duverger's law, while proportional representation tends to favour multi-party systems. Duverger himself did not treat this as an absolute rule, and smaller parties can still win many seats where their support is concentrated in particular regions.

Each system has its defenders. Supporters of two-party systems point to clear choices and single-party governments that voters can hold to account. Supporters of multi-party systems point to a wider range of views in parliament and governments built on parties that together represent more voters.