Next United Kingdom general election

The Sixth Periodic Review of Westminster constituencies, which proposed reducing the number of constituencies from 650 to 600, was commenced in 2011, but temporarily stopped in January 2013. Following the 2015 general election, each of the four parliamentary boundary commissions of the United Kingdom recommenced their review process in April 2016.[17][18][19] The four commissions submitted their final recommendations to the Secretary of State on 5 September 2018[20][21] and made their reports public a week later.[22][23][24][20] However, the proposals were never put forward for approval before the calling of the general election held on 12 December 2019, and in December 2020 the reviews were formally abandoned under the Schedule to the Parliamentary Constituencies Act 2020.[25]

A projection by psephologists Colin Rallings and Michael Thrasher of how the 2017 votes would have translated to seats under the 2018 boundaries suggested the changes would have been beneficial to the Conservative Party and detrimental to the Labour Party.[26][27]

In March 2020, Cabinet Office minister Chloe Smith confirmed that the 2023 Periodic Review of Westminster constituencies would be based on retaining 650 seats.[28][29] The previous relevant legislation was amended by the Parliamentary Constituencies Act 2020[30] and the four boundary commissions formally launched their 2023 reviews on 5 January 2021.[31][32][33][34] They were required to issue their final reports prior to 1 July 2023.[25] Once the reports have been laid before Parliament, Orders in Council giving effect to the final proposals must be made within four months, unless "there are exceptional circumstances". Prior to the Parliamentary Constituencies Act 2020, boundary changes could not be implemented until they were approved by both Houses of Parliament.

The boundary changes are expected to take effect from the end of October 2023, meaning that the general election will be contested on these new boundaries.[35]

The notional results of the 2019 election, if they had taken place under boundaries recommended by the Sixth Periodic Review.

The election will be fought under new constituency boundaries therefore creating a notional result from 2019, as if it had been fought on the boundaries established in 2023. These notional results will be important when calculating seat gains and losses.[36]

In England, seats in Northern England will be given to Southern England due to the large population growth. North West England and North East England will lose two seats each whereas South East England will gain 8 seats and South West England will gain 3 seats.[37] Due to historic voting patterns this is expected to help the Conservatives.[38] According to the notional results on the map, the Conservatives would have won Wirral West and Leeds North West instead of the Labour Party, but Labour would have won Pudsey and Filton and Bradley Stoke instead of the Conservatives. Liberal Democrat Tim Farron's Westmorland and Lonsdale constituency is now notionally a Conservative seat. The abolishment of Walsall North and Walsall South makes the all the seats in the Borough of Walsall notionally Conservative. The new seat of Spen Valley would be notionally Conservative despite being primarily created out a Labour constituency, Batley and Spen and the new seat of Blyth and Ashington would be notionally Labour despite the town of Blyth being moved out of a Conservative constituency, Blyth Valley.

In Scotland, the notional general election results would have had the following changes due to Scotland losing two seats.[39] The Scottish National Party is the most benefitting party from the boundary changes as they would have won 49 seats instead of 48. The Scottish Conservatives would have only won five seats instead of six. Scottish Labour would have retained Edinburgh South. Scottish Liberal Democrats would have only won two seats instead of four (Edinburgh West and Orkney and Shetland) under the new boundaries if they had been contested in the 2019 general election.

Under the new boundaries, Wales will lose 8 seats, and will only elect 32 MPs instead of 40 they elected in 2019. The dominant force in Wales, Welsh Labour, will reportedly benefit more from the boundary changes than the Conservatives.[40] Labour will win 18 instead of the 22 MPs they elected in 2019, but the Welsh Conservatives would be dramatically reduced from 14 down to 11. Due to the abolishment and merging of rural seats in West Wales, Plaid Cymru would have only won two instead of three.

In Northern Ireland, the notional results have an identical result to the 2019 general election in Northern Ireland.

The Scottish Liberal Democrats aim to use the ferry fiasco to regain their former seats in the Scottish Highlands.[41]

On 24 June 2023, at an event at the Caird Hall in Dundee, Humza Yousaf announced his support for using the general election as a referendum to demand Scottish independence.[42]

At the 2019 general election, in which the Conservatives won a majority of 80 seats, the manifesto of the party contained a commitment to repeal the Fixed-term Parliaments Act due to "paralysis at a time when the country has needed decisive action".[43] The pledge was confirmed in the first Queen's Speech following the election.[44]

In December 2020, the government published a draft Fixed-term Parliaments Act 2011 (Repeal) Bill, later retitled the Dissolution and Calling of Parliament Act 2022.[45]

The Dissolution and Calling of Parliament Act 2022 received royal assent on 24 March 2022 and entered into force the same day. The prime minister can again request the monarch to dissolve Parliament and call an early election with 25 working days' notice. Section 4 of the Act provided: "If it has not been dissolved earlier, a Parliament dissolves at the beginning of the day that is the fifth anniversary of the day on which it first met."

The Electoral Commission has confirmed that the 2019 Parliament must be dissolved, at the latest, by 17 December 2024, and that the next general election must take place no later than 28 January 2025.[46][47]

In September 2021, Oliver Dowden, the newly appointed chairman of the Conservative Party, told party staff to prepare for a general election. In March 2022, Dowden announced that the Conservatives would start a two-year election campaign in May, implying an election date of May 2024.[48] It was reported in April 2023 by The Telegraph that autumn 2024 was the preferred date of Prime Minister Rishi Sunak for the election to be held.[49] In September 2023, the announcement of Rishi Sunak's planned shift on green policies led many politicians and political pundits to believe it was essentially the beginning of an election campaign for May 2024.[50][51]

As of 26 October 2023, a total of 76 current members of Parliament have announced their intention not to stand for re-election (Conservative: 49, Labour: 14, Scottish National Party (SNP): 8, Independent: 3, Plaid Cymru: 1, Green: 1). Three MPs - Nadine Dorries (Conservative), Nigel Adams (Conservative), and Chris Pincher (Independent) - announced their intention not to stand again but later resigned from Parliament before the election.[52][53][54][55][56]

Some sitting MPs have not been selected by their party to recontest their seat (or a successor seat). Options available to these MPs include standing down, challenging their non-selection, seeking selection for another seat, and contesting the election under a different banner.

Due to boundary changes, most MPs standing for re-election will seek to represent a seat at least slightly different from their present seat. However, in some cases sitting MPs have secured selection to stand in a substantially or completely different seat from their present seat. They may happen because their seat is marginal and is likely to be lost by their party, boundary changes abolish their present seat or their present seat is redrawn in an unfavourable way in boundary changes.