Plaid Cymru ( ; ; , officially Plaid Cymru – the Party of Wales, and often referred to simply as Plaid) is a centre-left to left-wing Welsh nationalist political party in Wales, that supports Welsh independence from the United Kingdom. It campaigns on a platform of social democracy and civic nationalism. The party is a supporter of the European Union and is a member of the European Free Alliance (EFA). The party holds 4 of 32 Welsh seats in the UK House of Commons, 44 of 96 seats in the Senedd, and 200 of 1,234 principal local authority councillors. It is currently leading a minority government in Wales. Plaid was formed in 1925 under the name () and Gwynfor Evans won the first Westminster seat for the party at the 1966 Carmarthen by-election.
In 1999 (in the first devolved Welsh Assembly election), Plaid Cymru gained considerable ground in traditionally Labour heartlands. These breakthroughs were part of the intentional aim to win more seats in the Welsh valleys and North East Wales. The party have mostly been in opposition in the Senedd. Although under the leadership of Ieuan Wyn Jones, the party was part of a coalition as a junior partner with Welsh Labour between 2007 and 2011. Wyn Jones became the deputy First Minister and Minister for the Economy and Transport, alongside other Plaid MSs who also joined the cabinet.
After losses in the 2011 Assembly elections and dropping down to being the third largest party, Wyn Jones stepped down. He was succeeded by Leanne Wood. In the 2016 Assembly elections Wood managed to win her constituency seat of Rhondda meaning the party gained one seat, and became the official opposition once again, although only for a brief period. In 2018 following internal pressure and a leadership contest, Adam Price defeated Wood and was elected the new leader. Following the 2021 Senedd election Plaid formed a co-operation agreement with the Welsh Labour government. In May 2023 Price resigned as leader following the publication of a report which detailed failings by the party to prevent sexual harassment and bullying. In June 2023 Rhun ap Iorwerth was elected unopposed as leader. The party won both its target seats in the 2024 general election, therefore becoming the second largest party representing Wales in the House of Commons.
Plaid Cymru won a plurality in the 2026 Senedd election with 43 out of 96 seats, and have formed the current Welsh government, with Rhun ap Iorwerth becoming the first Plaid Cymru First Minister.
Ideology Plaid Cymru is a centre-left to left-wing party that heavily emphasises its Welsh character, having been described as regionalist, civic nationalist, left-wing nationalist, Welsh nationalist, and pro-independence.
Economically, the party gradually adopted a socialist line and welcomed many socialists since its founding, but formalised its goal of "decentralized socialism" only in 1981. The party has been described as democratic socialist and left-wing, and later as social democratic and centre-left, but in recent years the former party leader Leanne Wood has described herself as a socialist and the party has gradually been re-conceived as left-wing and also left-wing populist.
The party has been described as environmentalist, and opposes new nuclear power plants and nuclear weapons (including the UK's Trident nuclear weapons programme).
In May 2025, the party's leader, Rhun ap Iorwerth, stated there was no plan for an independence referendum in the first term of a Plaid Cymru government if they are elected at the 2026 Senedd election, and that talk of a referendum would not take place before 2030. However, the party continues to hold an official position favouring Welsh independence. At the party's October 2025 conference, the party's members backed a motion to establish a "standing commission" to develop a white paper on Welsh independence. However, leader Rhun ap Iorwerth has stated that the white paper would not be for Plaid's first term of government if they were elected, although the commission may still collect evidence for the white paper during a Plaid first term. A date was not given but it is suggested they may develop plans if Plaid win both the 2026 and 2030 Senedd elections. Ap Iorweth stated they aim to "kick start the national debate on independence", "take the discussion forward" and "call the referendum when the time is right", with members backing a statement that Wales was "on a journey to independence".
History
Beginnings
While both the Labour and Liberal parties of the early 20th century had accommodated demands for Welsh home rule, no political party existed for the purpose of establishing a Welsh government. was formed on 5 August 1925, by Moses Gruffydd, H. R. Jones and Lewis Valentine, members of ; ); and Fred Jones, Saunders Lewis of and D. Edmund Williams. Initially, home rule for Wales was not an explicit aim of the new movement; keeping Wales Welsh-speaking took primacy, with the aim of making Welsh the only official language of Wales.
Plaid Genedlaethol Cymru's principles (translated from Welsh), as of 1925, were as followed: "(to) Have a Welsh Wales, That includes;", "To preserve the Welsh language as the only living language of Wales, and to restore it as the official language in public life and administration throughout Wales", "To secure for the Welsh language a central place in the educational system of Wales, from elementary school to university", they outlined that they wanted Wales to be "a self-governing nation" and they would do so by having "Control over Welsh affairs through a national parliament elected by the people", "Representation in the League of Nations and the right to determine its own relationships as a member nation among the nations of the world", "Freedom from English political domination", have "Control over all local resources within Wales".Herald Cymraeg, Tuesday 02 June 1925 - https://www.britishnewspaperarchive.co.uk/viewer/bl/0003536/19250602/003/0003
In the 1929 general election, the party contested its first parliamentary constituency, Caernarvonshire, polling 609 votes, or 1.6% of the vote for that seat. The party contested few such elections in its early years, partly due to its ambivalence towards Westminster politics. Indeed, the candidate Lewis Valentine, the party's first president, offered himself in Caernarvonshire on a platform of demonstrating Welsh people's rejection of English dominion.
1930s By 1932, the aims of self-government and Welsh representation at the League of Nations had been added to that of preserving Welsh language and culture. However, this move, and the party's early attempts to develop an economic critique, did not broaden its appeal beyond that of an intellectual and socially conservative Welsh language pressure group.McAllister, L., Plaid Cymru: the Emergence of a Political Party (Seren, 2001), "The tentative moves towards elaborating and broadening Plaid's policy portfolio did not allow it to shake off its early identity as a language movement or a cultural pressure group." See also Philip, A. B., The Welsh Question (University of Wales Press, 1975), "It is clear that the Welsh Nationalist Party was at the outset essentially intellectual and moral in outlook and socially conservative." The alleged sympathy of the party's leading members (including President Saunders Lewis) towards Europe's totalitarian regimes compromised its early appeal further.Morgan, K. O., Welsh Devolution: the Past and the Future in Scotland and Wales: Nations Again? (ed. Taylor, B., and Thomson, K.), (1999), University of Wales Press. Williams, G. A. When Was Wales?, (1985), Penguin. Davies, J., A History of Wales, (1990, rev. 2007), Penguin. Davies, D. H., The Welsh Nationalist Party 1925–1945 (1983), St. Martin's Press. Morgan, K. O., Rebirth of a Nation, (1981), OUP.
Saunders Lewis, David John Williams and Lewis Valentine set fire to the newly constructed RAF Penyberth air base on the Llŷn Peninsula in Gwynedd in 1936, in protest at its siting in the Welsh-speaking heartland. The leaders' treatment, including the trial judge's dismissal of the use of Welsh and their subsequent imprisonment in Wormwood Scrubs, led to "The Three" becoming a cause célèbre. This heightened the profile of the party dramatically and its membership had doubled to nearly 2,000 by 1939.
1940s
Penyberth, and Plaid Cymru's neutral stance during the Second World War, prompted concerns within the UK Government that it might be used by Germany to insert spies or carry out other covert operations. In fact, the party adopted a neutral standpoint and urged (with only limited success) conscientious objection to war service.Davies, J., A History of Wales (1990, rev. 2007), Penguin: "Saunders Lewis ... hoped that a substantial number of Welshmen would refuse to be conscripted on the grounds that they were Welsh. He was disappointed by their response."
In 1943, Saunders Lewis contested the University of Wales parliamentary seat at a by-election, gaining 1,330 votes, or 22%. In the 1945 general election, with party membership at around 2,500, Plaid Cymru contested seven seats, as many as it had in the preceding 20 years, including constituencies in south Wales for the first time. At this time Gwynfor Evans was elected president.
1950s
Gwynfor Evans's presidency coincided with the maturation of Plaid Cymru (as it now began to refer to itself) into a more recognisable political party. Its share of the vote increased from 0.7% in the 1951 general election to 3.1% in 1955 and 5.2% in 1959. In the 1959 election, the party contested a majority of Welsh seats for the first time. Proposals to flood the village of Capel Celyn in the Tryweryn valley in Gwynedd in 1957 to supply the city of Liverpool with water played a part in Plaid Cymru's growth. The fact that the parliamentary bill authorising the dam went through without support from any Welsh MPs showed that the MPs' votes in Westminster were not enough to prevent such bills from passing.Davies, J., A History of Wales (1990, rev. 2007), Penguin.
1960s Support for the party declined slightly in the early 1960s, particularly as support for the Liberal Party began to stabilise from its long-term decline. In 1962, Saunders Lewis gave a radio talk entitled () in which he predicted the extinction of the Welsh language unless action was taken. This led to the formation of () the same year.Morgan, K. O., Rebirth of a Nation, (1981), OUP.
Labour's return to power in 1964 and the creation of the post of Secretary of State for Wales appeared to represent a continuation of the incremental evolution of a distinctive Welsh polity, following the Conservative government's appointment of a Minister of Welsh Affairs in 1951 and the establishment of Cardiff as Wales's capital in 1955.
However, in 1966, less than four months after coming in third in the constituency of Carmarthen, Gwynfor Evans captured the seat from Labour at a by-election. This was followed by two further by-elections in Rhondda West in 1967 and Caerphilly in 1968 in which the party achieved massive swings of 30% and 40% respectively, coming within a whisker of victory. The results were caused partly by an anti-Labour backlash. Expectations in coal mining communities that the Wilson government would halt the long-term decline in their industry had been dashed by a significant downward revision of coal production estimates.Francis, H. and Smith, D., The Fed: A History of the South Wales Miners in the Twentieth Century, (1980), University of Wales. However, particularly in Carmarthen, Plaid also successfully depicted Labour's policies as a threat to the viability of small Welsh communities.Tanner, D., Facing the New Challenge: Labour and Politics 1970–2000 in The Labour Party in Wales 1900–2000 (Ed. Tanner, D., Williams, C. and Hopkin, D.), (2000), University of Wales Press.
1970s