Negotiation positions following the UK's invocation of Article 50 of the Treaty on European Union in March 2017 to leave the EU were expected to feature significantly in the campaign, but did not as domestic issues took precedence instead.

[28] UKIP leader Paul Nuttall and First Minister of Wales Carwyn Jones criticised May for being opportunistic in the timing of the election, motivated by the then strong position of the Conservative Party in the opinion polls.

David Cameron, who had been the leader of the Conservative Party since 2005 and Prime Minister since 2010, was replaced in July 2016 by Theresa May following the referendum on the United Kingdom's membership of the European Union.

UKIP, then led by Nigel Farage, who was later replaced by Diane James and then by Paul Nuttall in 2016, won 12.7% of the vote in 2015 but gained only one MP, Douglas Carswell, who left the party in March 2017 to sit as an independent.

[65][67] Having devolved selections to its Scottish and Welsh parties, Labour's National Executive Committee endorsed all parliamentary candidates on 3 May except for Rochdale, the seat of suspended MP Simon Danczuk.

Zac Goldsmith was adopted as the candidate for Richmond Park, having lost the 2016 by-election as an independent in protest against the form of the Government's chosen expert's recommended Heathrow expansion.

[76] News coverage showed Aldridge balancing campaigning with revision for his A-level examinations, even missing the start of his end-of-year ball to speak at a hustings in Kendal.

[citation needed] Those ministers defeated in 2015 who stood for election in their former seats included Vince Cable in Twickenham, Ed Davey in Kingston and Surbiton, Jo Swinson in East Dunbartonshire, and Simon Hughes in Bermondsey and Old Southwark.

[89] Within a few days of the election being announced, the Green Party of England and Wales and the SNP each proposed to collaborate with Labour and the Liberal Democrats to prevent a Conservative majority government.

[102] Prior to the calling of the general election, the Liberal Democrats gained Richmond Park from the Conservatives in a by-election, a seat characterised by its high Remain vote in the 2016 EU referendum.

Talks on power-sharing between the DUP and Sinn Féin had failed to reach a conclusion, with Northern Ireland thus facing either another Assembly election, or the imposition of direct rule.

[142][143] On 6 June, May promised longer prison sentences for people convicted of terrorism and restrictions on the freedom of movement or deportation of militant suspects when it is thought they present a threat but there is not enough evidence to prosecute them, stating that she would change human rights laws to do so if necessary.

[177] May indicated that the Conservatives would maintain their net immigration target, and promised to implement a cap on "rip-off energy prices",[178][179] a policy that appeared in Labour's 2015 manifesto.

[183] On 14 May the Conservatives proposed a "new generation" of social housing, paid from the existing capital budget, offering funding to local authorities and changing compulsory purchase rules.

[197] Labour's proposal to employ 10,000 new police officers was overshadowed when Shadow Home Secretary Diane Abbott cited incorrect figures in a widely publicised gaffe in an LBC interview on 2 May on how it would be funded.

[198][199] Labour later stated that the £300 million cost would be funded by reversing cuts to capital gains taxes, although it was noted that the party had also pledged some of those savings towards other expenditure plans.

[215][216] Compared to the leaked draft, the manifesto was noted for toughening Labour's position on defence and Trident, confirming that outside the EU free movement would have to end, qualifying support for airport expansion, and clarifying the party's stance on Israel-Palestine, as well as other changes.

[220][221] The SNP, keen to maintain its position as the third-largest party in the House of Commons, made the need to protect Scotland's interests in the Brexit negotiations a central part of its campaign.

[240] Paul Nuttall announced that UKIP's manifesto would seek to ban the burqa, outlaw sharia law, impose a temporary moratorium on new Islamic schools and require annual checks against female genital mutilation (FGM) for high-risk girls.

[297][290][298][299][296] During the election period, BBC Question Time host David Dimbleby said Jeremy Corbyn had not had 'a fair deal at the hands of the press' and that he was more popular than the media made him out to be.

[299] While the collective voice of the right-wing papers were (four times) stronger in their support for the Conservatives than the left-wing were of Labour, on the whole they were similar to the left in their negativity towards, or avoidance of, the leader of their endorsed party.

[324][298][314] In a YouGov poll, 42% of the general public said that TV was most influential in helping them choose, or confirming their choice in, whom to vote for; 32% said newspapers and magazines; 26%, social media; and 25%, radio.

In Scotland, the Conservatives, Labour, and the Liberal Democrats all gained seats from the SNP, whose losses were attributed to opposition to a second Scottish independence referendum, contributing to tactical voting for unionist parties.

[408] UKIP failed to win any seats, its vote share falling from 12.6% at the previous general election to just 1.8%; party leader Paul Nuttall came third in Boston and Skegness.

[410][411] Research company Ipsos MORI considered age to be one of the most significant factors behind the result; compared to the 2015 general election, under-45s tended to opt more for Labour and over-54s for the Conservatives.

[411] Published in August 2017, the British Election Study (BES), which surveyed 30,000 voters, found that despite a relatively low profile in the campaign, Brexit was considered to be the single most important issue facing the country by over a third of respondents.

[425] Labour has had increased appeal to voters who work in areas central to the modern British economy, and at the same time in larger metropolitan centres and economically dynamic university towns.

[444][445][446] In April 2020, Sky News's Tom Rayner and The Independent's Jon Stone reported on an 860-page dossier into the handing of allegations of antisemitism by Labour members and officials.

[455] In July, Prime Minister Theresa May admitted she had "shed a tear" upon seeing the election exit poll, and suggested the manifesto's lack of appeal to younger voters had played a part in Conservative shortcomings.

[456] In 2018, an investigation by Swansea University and The Sunday Times revealed that 6,500 Russian Twitter accounts, at least many of which were bots, supported Labour, denigrated Conservatives, and reached millions of voters.