Electoral Commission (United Kingdom) in the context of Political party in the United Kingdom

There are five types of elections in the United Kingdom: elections to the House of Commons of the United Kingdom (commonly called 'general elections' when all seats are contested), elections to devolved parliaments and assemblies, local elections, mayoral elections, and Police and Crime Commissioner elections. Within each of those categories, there may also be by-elections. Elections are held on Election Day, which is conventionally a Thursday, and under the provisions of the Dissolution and Calling of Parliament Act 2022 the timing of general elections can be held at the discretion of the prime minister during any five-year period. All other types of elections are held after fixed periods, though early elections to the devolved assemblies and parliaments can occur in certain situations. The five electoral systems used are: the single member plurality system (first-past-the-post), the multi-member plurality, the single transferable vote, the additional member system, and the supplementary vote.

Elections are administered locally: in each lower-tier local authority, the polling procedure is operated by the returning officer or acting returning officer, and the compiling and maintenance of the electoral roll by the electoral registration officer (except in Northern Ireland, where the Electoral Office for Northern Ireland assumes both responsibilities). The Electoral Commission sets standards for and issues guidelines to returning officers and electoral registration officers, and is responsible for nationwide electoral administration (such as the registration of political parties and directing the administration of national referendums).

Britain Stronger in Europe (formally The In Campaign Limited) was an advocacy group which campaigned in favour of the United Kingdom's continued membership of the European Union in the 2016 British referendum. It was launched at the Old Truman Brewery in London on 12 October 2015, and declared as the official "Remain" campaign for the referendum by the Electoral Commission on 13 April 2016.

In the 2016 United Kingdom European Union membership referendum, 51.9% voted in favour of leaving the EU, which meant that the Britain Stronger in Europe campaign was unsuccessful in achieving its main goal.

Vote Leave was a campaigning organisation that supported a "Leave" vote in the 2016 United Kingdom European Union membership referendum. On 13 April 2016 it was designated by the Electoral Commission as the official campaign in favour of leaving the European Union in the Referendum.

Vote Leave was founded in October 2015 by political strategists Matthew Elliott and Dominic Cummings as a cross-party campaign. It involved Members of Parliament from the Conservative Party, Labour Party and the sole UKIP MP, Douglas Carswell along with MEP Daniel Hannan and the Conservative peer Nigel Lawson. Labour MP Gisela Stuart served as chairman and Leader of the Vote Leave Campaign Committee as Co-Convenor with Michael Gove MP, of the Conservatives. The campaign was also supported by a number of prominent politicians; including outgoing Mayor of London Boris Johnson, who became a key figurehead for the Vote Leave campaign. A number of Vote Leave principals, including Douglas Carswell, Michael Gove, Bernard Jenkin and Anne-Marie Trevelyan, were also members of the influential IPSA resourced European Research Group.

The 2016 United Kingdom European Union membership referendum took place in the United Kingdom and Gibraltar on 23 June 2016. Membership of the European Union had been a topic of political debate in the United Kingdom since the country joined the European Communities (then commonly referred to as the "Common Market" by the British people) in 1973. This referendum was conducted very differently from the European Communities membership referendum in 1975; a more localised and regionalised counting procedure was used, and the ballot was overseen by the Electoral Commission, a public body that did not exist at the time of the first vote. This article lists, by voting area for Great Britain and Gibraltar and by parliamentary constituency for Northern Ireland, all the results of the referendum, each ordered into national and regional sections.

Under the provisions of the European Union Referendum Act 2015, there were a total of 382 voting areas across twelve regions, using the same boundaries as used in European Parliamentary elections since 1999, under the provisions of the European Parliamentary Elections Act 2002, with votes counted at local authority level. In England the 326 local government districts were used as the voting areas; these consist of all unitary authorities, all metropolitan boroughs, all shire districts, the London boroughs, the City of London and the Isles of Scilly. The nine regions of England were then also used to count the votes at the regional level, with Gibraltar being regarded as part of South West England. Northern Ireland was a single voting area as well as being a regional count, although local totals by Westminster parliamentary constituency area were announced. In Scotland the 32 Scottish council areas were used as voting areas, and there was a single national count. In Wales the 22 Welsh council areas were used as the voting areas, and there was a single national count.

The Electoral Commission's Register of Political Parties lists the details of political parties registered to contest elections in the United Kingdom, including their registered name. Under current electoral law, including the Registration of Political Parties Act 1998, the Electoral Administration Act 2006, and the Political Parties, Elections and Referendums Act 2000, only registered party names can be used on ballot papers by those wishing to contest elections. Candidates who do not belong to a registered party can use "independent" or no label at all. As of 25 May 2024, the Electoral Commission showed the number of registered political parties in Great Britain and Northern Ireland as 393.

Before the middle of the 19th century, politics in the United Kingdom was dominated by the Whigs and the Tories. These were not political parties in the modern sense but somewhat loose alliances of interests and individuals. The Whigs included many of the leading aristocratic dynasties committed to the Protestant succession, and later drew support from elements of the emerging industrial interests and wealthy merchants, while the Tories were associated with the landed gentry, the Church of England and the Church of Scotland.

There are a number of political parties registered to the Electoral Commission in Wales. Some of these parties have elected representation in the Senedd (Welsh Parliament; Welsh: Senedd Cymru) and/or in Westminster (UK Parliament) and some have elected representation in one or more of the 22 Welsh local authorities, while others have entirely no elected representation. This Wikipedia page lists all of the above and some relevant Welsh political parties that formerly existed but have since disbanded. The largest political parties typically reside in either the House of Commons or the Senedd, the current largest party in Wales is Welsh Labour, followed closely by the Welsh Conservatives and Plaid Cymru.