The 2019 United Kingdom general election was held on Thursday 12 December 2019, with 47,074,800 registered voters entitled to vote to elect 650 Members of Parliament (MPs) to the House of Commons. The governing Conservative Party, led by Prime Minister Boris Johnson, won a landslide victory with a majority of 80 seats, a net gain of 48, on 43.6 per cent of the popular vote, the highest percentage for any party since the 1979 general election, though with a narrower popular vote margin than that achieved by the Labour Party over the Conservatives at the 1997 general election. This was the second national election to be held in 2019 in the United Kingdom, the first being the 2019 European Parliament election. 
After it lost its parliamentary majority at the 2017 general election, the Conservative Party governed in minority with the support of the Democratic Unionist Party (DUP). The prime minister, Theresa May, resigned in July 2019 after repeatedly failing to pass her Brexit withdrawal agreement in parliament. Johnson succeeded her as the leader of the Conservative Party and as prime minister in July 2019. Johnson could not persuade Parliament to approve a revised withdrawal agreement by the end of October, and chose to call a snap election, which the House of Commons supported under the Early Parliamentary General Election Act 2019. Opinion polls showed a firm lead for the Conservatives against the opposition Labour Party throughout the campaign.
The Conservatives won 365 seats, their highest number and proportion since the 1987 general election, and recorded their highest share of the popular vote since 1979; many of their gains were made in seats once considered previously safe for Labour, dubbed the red wall, which had voted strongly in favour of British withdrawal from the EU in the 2016 European Union (EU) membership referendum. Labour won 202 seats, its fewest since the 1935 general election. The Scottish National Party (SNP) made a net gain of 13 seats with 45 per cent of the vote in Scotland, winning 48 of the 59 seats there. The Liberal Democrats increased their vote share to 11.6 per cent, but won only 11 seats, a net loss of one since the last election. The party's leader, Jo Swinson, lost her seat to the SNP, thus triggering the 2020 party leadership election, which was won by Ed Davey. The DUP won a plurality of seats in Northern Ireland. The Social Democratic and Labour Party (SDLP) and the Alliance Party of Northern Ireland (APNI) regained parliamentary representation as the DUP lost seats.
The election result gave Johnson the mandate he sought from the electorate to formally implement the withdrawal of the United Kingdom from the European Union, and to complete the repeal of the European Communities Act 1972 on 31 January 2020. Jeremy Corbyn, Labour's leader at the election, resigned, triggering the 2020 party leadership election, which was won by his shadow Brexit secretary, Keir Starmer. Jane Dodds, the Liberal Democrats' leader in Wales, was also unseated in Brecon and Radnorshire. In Northern Ireland, Irish nationalist MPs outnumbered unionists for the first time, although the unionist popular vote remained higher at 43.1 per cent, and the seven Sinn Féin MPs did not take their seats due to their tradition of abstentionism. 
Despite being elected with a large majority, Johnson went on to resign amid a government crisis in 2022, being followed by Liz Truss for fifty days and then by Rishi Sunak, who went on to lead the Conservatives to a landslide defeat in the subsequent election. This was the last election to be held under the reign of Elizabeth II.
Background.
In July 2016, Theresa May was elected Prime Minister to succeed David Cameron, who had resigned following the 2016 Brexit referendum. The Conservative Party had governed since the 2010 general election, initially in coalition with the Liberal Democrats and then alone with a small majority following the 2015 general election. In the 2017 general election, May lost her majority but was able to resume office as a result of a confidence and supply agreement with Northern Ireland's Democratic Unionist Party (DUP), known as the Conservative–DUP agreement. In the face of opposition from the DUP and Conservative backbenchers, the second May ministry was unable to pass its Brexit withdrawal agreement by 29 March 2019, so some political commentators considered that an early general election was likely.
The opposition Labour Party called for a 2019 vote of confidence in the May ministry but the motion, held in January, failed. May resigned following her party's poor performance in the 2019 European Parliament election during the first extension granted by the European Union for negotiations on the withdrawal agreement. Boris Johnson won the 2019 Conservative leadership election and became the prime minister on 24 July 2019. Along with attempting to revise the withdrawal agreement arranged by his predecessor's negotiations, Johnson made three attempts to hold a snap election under the process defined in the Fixed-term Parliaments Act 2011, which required a two-thirds supermajority in order for an election to take place.
All three attempts to call an election failed to gain support; Parliament insisted that Johnson "take a no-deal Brexit off the table first" and secure a negotiated Withdrawal Agreement, expressed in particular by its enactment against his will of the European Union (Withdrawal) (No. 2) Act 2019, often called the Benn Act, after Labour MP Hilary Benn, who introduced the bill. After failing to pass a revised deal before the first extension's deadline of 31 October 2019, Johnson agreed to a second extension on negotiations with the European Union and finally secured a revised withdrawal agreement.
Parliament agreed to an election through a motion proposed by the Liberal Democrats and the Scottish National Party (SNP) on 28 October. The Early Parliamentary General Election Act 2019 (EPGEA) was passed in the House of Commons by 438 votes to 20; an attempt to pass an amendment by opposition parties for the election to be held on 9 December failed by 315 votes to 295. The House of Lords followed suit on 30 October, with royal assent made the day after for the ratification of the EPGEA.
Date of the election.
The deadline for candidate nominations was 14 November 2019, with political campaigning for four weeks until polling day on 12 December. On the day of the election, polling stations across the country were open from 7 am, and closed at 10 pm. The date chosen for the 2019 general election made it the first to be held in December since the 1923 general election.
Voting eligibility.
Individuals eligible to vote had to be registered to vote by midnight on 26 November. To be eligible to vote, individuals had to be aged 18 or over; residing as an Irish or Commonwealth citizen at an address in the United Kingdom, or be a British citizen overseas who registered to vote in the last 15 years; and not legally excluded (on grounds of detainment in prison, a mental hospital, or on the run from law enforcement), or disqualified from voting. Anyone who qualified as an anonymous elector had until midnight on 6 December to register.
Contesting political parties and candidates.
Most candidates are representatives of a political party, which must be registered with the Electoral Commission's Register. Those who do not belong to one must use the label "Independent" or none. In the 2019 election 3,415 candidates stood: 206 being independents, the rest representing one of 68 political parties.
Campaign.
Campaign background.
The Conservative Party and Labour Party have been the two biggest political parties, and have supplied every Prime Minister since the 1922 general election. The Conservative Party have governed since the 2010 election, in coalition with the Liberal Democrats from 2010 to 2015. At the 2015 general election, the Conservative Party committed to offering a referendum on whether the United Kingdom should leave the European Union (EU) and won a majority in that election. A referendum was held in June 2016, and the Leave campaign won by 51.9% to 48.1%.
United Kingdom invocation of Article 50 of the Treaty on European Union came in March 2017, and Theresa May triggered a snap election in 2017, in order to demonstrate support for her planned negotiation of Brexit. Instead, the Conservative Party lost seats. They won a plurality of MPs but not a majority, and the result was a hung parliament. They formed a minority government, with the Democratic Unionist Party (DUP) as their confidence and supply partner. Neither May nor her successor Boris Johnson, the winner of the 2019 Conservative leadership election, was able to secure parliamentary support either for a deal on the terms of the country's exit from the EU, or for exiting the EU without an agreed deal. Johnson later succeeded in bringing his withdrawal agreement to a second reading in Parliament, following another extension until January 2020. 
After Johnson's 2019 win, a new Withdrawal Agreement Bill was introduced in 2020. Compared to its 2019 October predecessor, this bill offered, in the words of political scientist Meg Russell, "significantly weaker parliamentary oversight of Brexit ... giving parliament no formal role in agreeing the future relationship negotiating objectives, and a diminished role in approving any resulting treaty."
During the lifespan of the 2017 Parliament, twenty MPs resigned from their parties, mostly due to disputes with their party leaderships; some formed new parties and alliances. In February 2019, eight Labour and three Conservative MPs left their parties to sit together as The Independent Group. Having undergone a split and two name changes, at dissolution, this group numbered five MPs who sat as the registered party The Independent Group for Change under the leadership of Anna Soubry. 
Two MPs sat in a group called The Independents, which at its peak had five members. One MP created the Birkenhead Social Justice Party, while a further 20 MPs who began as Labour or Conservative ended Parliament as unaffiliated independents. Seven MPs, from both the Conservatives and Labour, joined the Liberal Democrats during Parliament, in combination with a gain after the 2019 Brecon and Radnorshire by-election. By the time Parliament was dissolved, the Liberal Democrats had raised their number from 12 at the election to 20 at dissolution.
One reason for the defections from the Labour Party was the ongoing row over alleged antisemitism in the Labour Party. Labour entered the election campaign while under investigation by the Equality and Human Rights Commission. The Jewish Labour Movement declared that it would not generally campaign for Labour. The Conservative Party was also criticised for not doing enough to tackle the alleged Islamophobia in the Conservative Party. The Conservatives ended the previous parliamentary period with fewer seats than they had started with because of defections and also saw the 2019 suspension of rebel Conservative MPs for going against the party line by voting to prevent a no-deal Brexit. Of the 21 expelled, 10 were subsequently reinstated, while the others continued as independents.
Policy positions.
Brexit.
The major parties had a wide variety of stances on Brexit. The Conservative Party supported leaving under the terms of the withdrawal agreement as negotiated by Johnson (amending May's previous agreement), and this agreement formed a central part of the Conservative campaign via the slogan "Get Brexit Done". The Brexit Party was in favour of a no-deal Brexit, with its leader Nigel Farage calling for Johnson to drop the deal.
The Conservative manifesto read "If we elect a majority of Conservative MPs to Parliament, we will start putting our deal through Parliament before Christmas and we will leave the European Union in January" which ultimately happened.
The Labour Party proposed a renegotiation of the withdrawal agreement, towards a closer post-withdrawal relationship with the EU, and would then put this forward as an option in a referendum alongside the option of remaining in the EU. The Labour Party's campaigning stance in that referendum would be decided at a special conference. In a "Question Time" special featuring four party leaders, Labour leader Jeremy Corbyn said that he would stay neutral in the referendum campaign.
The Liberal Democrats, Scottish National Party, Plaid Cymru, The Independent Group for Change, and the Green Party of England and Wales were all opposed to Brexit, and proposed that a further referendum be held with the option, for which they would campaign, to remain in the EU. The Liberal Democrats originally pledged that if they formed a majority government, which was considered a highly unlikely