2023 review of Westminster constituencies

[5] Local election offices are funded to implement mitigating measures to minimise any such disproportionate impacts.

[4] The Command Papers were sponsored and ordered by the Deputy Prime Minister, Nick Clegg, a Liberal Democrat.

Following three rounds of public consultation, all four commissions submitted their final proposals to the Speaker of the House of Commons on 27 June 2023.

The Speaker immediately laid these before Parliament and the reports were published on the respective commissions' websites the following day.

[6] The new boundaries were formally introduced into UK law on 15 November 2023 through The Parliamentary Constituencies Order 2023.

[7] (The original deadline of the end of October was missed by the government, which, according to the Act, must only happen in exceptional circumstances).

[12] The commissions jointly calculated the relevant electoral quota/range to be used for the 2023 review and the allocation of parliamentary constituencies between the four nations.

[13] The Boundary Commission for England applied the same distribution formula to the English allocation, which results in the following redistribution of constituencies among the English regions:[13] * Excluding Isle of Wight All four commissions submitted their Final Recommendations Reports to the speaker of the House of Commons on 27 June 2023.

As the number of constituencies in Northern Ireland remains the same, changes were only necessary to bring some of the electorates within the permitted range and align boundaries with those of revised local government wards.

If the 2019 general election was re-run under the boundaries in the final proposals, it was estimated that a further 15 seats would change hands.

[32] This was further analysed as follows: In January 2024, professors Colin Rallings and Michael Thrasher published detailed estimates of what the result would have been had the new boundaries been in place at the previous general election.

This analysis shows the Conservatives would have won seven additional seats in 2019, with Labour losing two, the Liberal Democrats three and Plaid Cymru two.

There are a total of 187 linked constituencies, many of which involve significant changes resulting from the knock-on impact of new or abolished seats within review areas.

Researchers Michael Thrasher and Colin Rallings have calculated the notional results of the 2019 United Kingdom general election if it had taken place under the new constituency borders.