2023 review of Westminster constituencies

Individual registration

The 2023 review was the successor to the 2018 periodic review of Westminster constituencies, which was abandoned after it failed to pass into law. After abandonment of several previous reviews since 2015, the 2023 review was set to be the first review based on electoral registers drawn up using Individual Electoral Registration, which Parliament approved from 2014 to 2015. Because every routine canvass by local government reaches slightly fewer imminent attainers of the age of 18 than the previous system of household registration, the new system favours the Conservatives, according to a University of Manchester researcher in 2023. Local election offices are funded to implement mitigating measures to minimise any such disproportionate impacts. The Command Papers were sponsored and ordered by the Deputy Prime Minister of the Cameron-Clegg coalition, Nick Clegg, a Liberal Democrat.

Process

Under current legislation, the four boundary commissions of the United Kingdom were required to report on their next review of the boundaries of parliamentary constituencies before 1 July 2023. In order to meet this deadline, the commissions began their work on 5 January 2021. 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. The new boundaries were formally introduced into UK law on 15 November 2023 through The Parliamentary Constituencies Order 2023. (The original deadline of the end of October was missed by the government, which, according to the Act, must only happen in exceptional circumstances).

A description of the review process is detailed in timeline of the 2023 periodic review of Westminster constituencies.

Size of constituencies

The four boundary commissions launched their 2023 reviews on 5 January 2021, to coincide with the release by the Office for National Statistics (ONS) of electorate data from analysis of the electoral registers that had been published on 2 March 2020. 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. The English commission further divided its allocation between the nine regions of England.

The electorate of the United Kingdom, comprising 650 constituencies, as determined by the ONS, was 47,558,398 on 2 March 2020. The electorate of the five protected constituencies – Isle of Wight (two seats), Na h-Eileanan an Iar, Orkney and Shetland, and Ynys Môn – amounted to 220,132, leaving 47,338,266 to be distributed between the remaining 645 constituencies, which gave an electoral quota of 73,393. Each non-protected constituency must have an electorate which is within 5% of this quota, which gave a permitted range of 69,724 to 77,062. In Northern Ireland the legislation allows for a wider range, in certain prescribed circumstances, from 68,313 to 77,062.

Distribution of seats

United Kingdom

The 650 constituencies were allocated between the four nations of the UK in accordance with the Sainte-Laguë method as shown in the table below.

Regions of England

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:

* Excluding Isle of Wight

Final proposals

All four commissions submitted their Final Recommendations Reports to the speaker of the House of Commons on 27 June 2023. These were immediately laid before Parliament and the reports were published on the respective commissions' websites on 28 June 2023.

England

The final recommendations for England resulted in only 55 of the existing 533 constituencies remaining completely unchanged.

In Wales, 21 of the 32 seats were unaltered from the revised proposals; 10 had revised boundaries (of which five were renamed); and one had a name change only. In Scotland boundary changes affected 18 seats, of which 12 were renamed. Only name changes affected a further six, leaving 33 unaltered. In Northern Ireland, minor boundary changes affected five seats, with no changes to the proposed names.

Northern Ireland

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. Belfast South was enlarged into the countryside and renamed Belfast South and Mid Down. East Antrim was extended further west, while Fermanagh and South Tyrone was extended further east into County Armagh.

Demographic changes from new boundaries

This table describes how the demographics of each constituency are different under the new boundaries compared to the old boundaries. The population disparity between constituencies exists because boundaries are drawn based on electorate size, not total population.

Scotland

The following table details the proposed changes, based on the commission's final report.

Wales

The final recommendations on the new constituencies in Wales were published on 28 June 2023 by the Boundary Commission for Wales. This followed years of proposals and consultations since 2021, with initial proposals published in 2021 and revised in 2022.

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Political impact

According to analysis carried out by electoral modelling consultancy Electoral Calculus, a total of 24 constituencies would disappear (i.e. be broken up and not form the larger part of any proposed seats), offset by 24 wholly new constituencies (proposed seats which do not contain the larger part of any pre-existing seat). 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. The overall effect would be a net gain of 11 seats for the Conservatives, a net loss of 6 for Labour, a loss of 3 for the Liberal Democrats and 2 for Plaid Cymru. 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.

New and abolished constituencies

In total, the review produced 211 newly named constituencies, with the same number of seat names no longer being used (comprising just under one third of the total of 650). These constituencies are listed alphabetically below. Note that a constituency name remaining the same or changing does not necessarily correlate with how much the seat's boundaries change, or whether the constituency would be seen as a "new constituency". For example, the pre-2023 Burton changes name to become the post-2023 Burton and Uttoxeter, but its boundaries remain identical; on the other hand, the constituency name Newcastle upon Tyne North remains the same after the review, but the majority of the post-review constituency covers different territory to the pre-review constituency, with only 43% of the pre-2023 Newcastle upon Tyne North remaining in the new seat after the review.

New constituency names

Following the publication of the final recommendations, the names of constituencies were introduced or re-introduced at the 2024 general election:

• Aberafan Maesteg
• Aberdeenshire North and Moray East
• Alloa and Grangemouth
• Angus and Perthshire Glens
• Arbroath and Broughty Ferry
• Argyll, Bute and South Lochaber
• Bangor Aberconwy
• Barnsley North
• Barnsley South
• Bathgate and Linlithgow
• Beckenham and Penge
• Belfast South and Mid Down
• Bethnal Green and Stepney
• Bicester and Woodstock
• Birmingham Hall Green and Moseley
• Birmingham Hodge Hill and Solihull North
• Blackley and Middleton South
• Blackpool North and Fleetwood
• Blaenau Gwent and Rhymney
• Blaydon and Consett
• Blyth and Ashington
• Bolton South and Walkden
• Brecon, Radnor and Cwm Tawe
• Brent East
• Brent West
• Bridgwater
• Bridlington and The Wolds
• Brigg and Immingham
• Brighton Kemptown and Peacehaven
• Bristol Central
• Bristol North East
• Broadland and Fakenham
• Bromley and Biggin Hill
• Buckingham and Bletchley
• Burton and Uttoxeter
• Bury St Edmunds and Stowmarket
• Caerfyrddin
• Cardiff East
• Ceredigion Preseli
• Chester North and Neston
• Chester South and Eddisbury
• Clapham and Brixton Hill
• Clwyd East
• Clwyd North
• Coatbridge and Bellshill
• Corby and East Northamptonshire
• Coventry East
• Cowdenbeath and Kirkcaldy
• Cramlington and Killingworth
• Croydon East
• Croydon West
• Cumbernauld and Kirkintilloch
• Dewsbury and Batley
• Didcot and Wantage
• Doncaster East and the Isle of Axholme
• Dorking and Horley
• Dover and Deal
• Droitwich and Evesham
• Dudley
• Dundee Central
• Dunfermline and Dollar
• Dunstable and Leighton Buzzard
• Earley and Woodley
• East Grinstead and Uckfield
• East Kilbride and Strathaven
• East Thanet
• East Wiltshire
• Edinburgh East and Musselburgh
• Edmonton and Winchmore Hill
• Ellesmere Port and Bromborough
• Eltham and Chislehurst
• Ely and East Cambridgeshire
• Exmouth and Exeter East
• Fareham and Waterlooville
• Farnham and Bordon
• Frome and East Somerset
• Gateshead Central and Whickham
• Glasgow West
• Glastonbury and Somerton
• Glenrothes and Mid Fife
• Godalming and Ash
• Goole and Pocklington
• Gordon and Buchan
• Gorton and Denton
• Grantham and Bourne
• Great Grimsby and Cleethorpes
• Halesowen
• Hamble Valley
• Hamilton and Clyde Valley
• Hammersmith and Chiswick
• Hampstead and Highgate
• Harborough, Oadby and Wigston
• Harpenden and Berkhamsted
• Henley and Thame
• Herne Bay and Sandwich
• Heywood and Middleton North
• Hinckley and Bosworth
• Hitchin
• Honiton and Sidmouth
• Hornsey and Friern Barnet
• Hove and Portslade
• Inverclyde and Renfrewshire West
• Inverness, Skye and West Ross-shire
• Isle of Wight East
• Isle of Wight West
• Jarrow and Gateshead East
• Keighley and Ilkley
• Kensington and Bayswater
• Kingston upon Hull North and Cottingham
• Kingston upon Hull West and Haltemprice
• Kingswinford and South Staffordshire
• Lancaster and Wyre
• Leeds Central and Headingley
• Leeds South
• Leeds South West and Morley
• Leeds West and Pudsey
• Leigh and Atherton
• Lewisham North
• Lewisham West and East Dulwich
• Liverpool Garston
• Lothian East
• Lowestoft
• Luton South and South Bedfordshire
• Maidstone and Malling
• Manchester Rusholme
• Melksham and Devizes
• Melton and Syston
• Meriden and Solihull East
• Merthyr Tydfil and Aberdare
• Mid and South Pembrokeshire
• Mid Buckinghamshire
• Mid Cheshire
• Mid Dunbartonshire
• Mid Leicestershire
• Middlesbrough and Thornaby East
• Milton Keynes Central
• Monmouthshire
• Montgomeryshire and Glyndŵr
• Moray West, Nairn and Strathspey
• Motherwell, Wishaw and Carluke
• Neath and Swansea East
• Newcastle upon Tyne Central and West
• Newcastle upon Tyne East and Wallsend
• Newport West and Islwyn
• Newton Aycliffe and Spennymoor
• Normanton and Hemsworth
• North Bedfordshire
• North Cotswolds
• North East Somerset and Hanham
• North Northumberland
• North Warwickshire and Bedworth
• North West Essex
• Nottingham North and Kimberley
• Oldham West, Chadderton and Royton
• Ossett and Denby Dale
• Peckham
• Pendle and Clitheroe
• Penrith and Solway
• Perth and Kinross-shire
• Pontefract, Castleford and Knottingley
• Queen's Park and Maida Vale
• Rawmarsh and Conisbrough
• Reading Central
• Reading West and Mid Berkshire
• Rhondda and Ogmore
• Richmond and Northallerton
• Runcorn and Helsby
• Rutherglen
• Rutland and Stamford
• Salford
• Selby
• Sherwood Forest
• Shrewsbury
• Smethwick
• Solihull West and Shirley
• South Cotswolds
• South Devon
• South Shropshire
• Southend East and Rochford
• Southend West and Leigh
• Southgate and Wood Green
• Spen Valley
• St Neots and Mid Cambridgeshire
• Stirling and Strathallan
• Stockton West
• Stone, Great Wyrley and Penkridge
• Stratford and Bow
• Streatham and Croydon North
• Sussex Weald
• Swindon North
• Swindon South
• Taunton and Wellington
• Tipton and Wednesbury
• Tiverton and Minehead
• Tonbridge
• Torridge and Tavistock
• Vauxhall and Camberwell Green
• Wakefield and Rothwell
• Walsall and Bloxwich
• Washington and Gateshead South
• Waveney Valley
• Weald of Kent
• Wetherby and Easingwold
• Wellingborough and Rushden
• Wells and Mendip Hills
• West Bromwich
• West Ham and Beckton
• Whitehaven and Workington
• Widnes and Halewood
• Wolverhampton West
• Worsley and Eccles

Abolished constituency names

The following constituency names disappeared at the 2024 general election:

• Aberavon
• Aberconwy
• Angus
• Arfon
• Argyll and Bute
• Banff and Buchan
• Barnsley Central
• Barnsley East
• Batley and Spen
• Beckenham
• Belfast South
• Berwick-upon-Tweed
• Bethnal Green and Bow
• Birmingham Hall Green
• Birmingham Hodge Hill
• Blackley and Broughton
• Blackpool North and Cleveleys
• Blaenau Gwent
• Blaydon
• Blyth Valley
• Bolton South East
• Bosworth
• Brecon and Radnorshire
• Brent Central
• Brent North
• Bridgwater and West Somerset
• Brigg and Goole
• Brighton Kemptown
• Bristol West
• Broadland
• Bromley and Chislehurst
• Buckingham
• Burton
• Bury St Edmunds
• Camberwell and Peckham
• Cardiff Central
• Carmarthen East and Dinefwr
• Carmarthen West and South Pembrokeshire
• Ceredigion
• Charnwood
• City of Chester
• Cleethorpes
• Clwyd South
• Clwyd West
• Coatbridge, Chryston and Bellshill
• Copeland
• Corby
• Coventry North East
• Croydon Central
• Croydon North
• Cumbernauld, Kilsyth and Kirkintilloch East
• Cynon Valley
• Delyn
• Denton and Reddish
• Devizes
• Dewsbury
• Don Valley
• Dover
• Dudley North
• Dudley South
• Dundee East
• Dundee West
• Dunfermline and West Fife
• East Devon
• East Dunbartonshire
• East Kilbride, Strathaven and Lesmahagow
• East Lothian
• East Yorkshire
• Eddisbury
• Edinburgh East
• Edmonton
• Ellesmere Port and Neston
• Elmet and Rothwell
• Eltham
• Enfield Southgate
• Fareham
• Garston and Halewood
• Gateshead
• Glasgow Central
• Glasgow North West
• Glenrothes
• Gordon
• Grantham and Stamford
• Great Grimsby
• Halesowen and Rowley Regis
• Haltemprice and Howden
• Halton
• Hammersmith
• Hampstead and Kilburn
• Harborough
• Hemsworth
• Henley
• Heywood and Middleton
• Hitchin and Harpenden
• Hornsey and Wood Green
• Hove
• Inverclyde
• Inverness, Nairn, Badenoch and Strathspey
• Isle of Wight
• Islwyn
• Jarrow
• Keighley
• Kensington
• Kingston upon Hull North
• Kingston upon Hull West and Hessle
• Kingswood
• Kirkcaldy and Cowdenbeath
• Lanark and Hamilton East
• Lancaster and Fleetwood
• Leeds Central
• Leeds West
• Leigh
• Lewisham Deptford
• Lewisham West and Penge
• Linlithgow and East Falkirk
• Ludlow
• Luton South
• Maidstone and The Weald
• Manchester Gorton
• Meon Valley
• Meriden
• Merthyr Tydfil and Rhymney
• Mid Worcestershire
• Middlesbrough
• Milton Keynes South
• Mole Valley
• Monmouth
• Montgomeryshire
• Moray
• Morley and Outwood
• Motherwell and Wishaw
• Neath
• Newcastle upon Tyne Central
• Newcastle upon Tyne East
• Newport West
• Normanton, Pontefract and Castleford
• North East Bedfordshire
• North East Somerset
• North Swindon
• North Thanet
• North Tyneside
• North Warwickshire
• North West Durham
• North Wiltshire
• Nottingham North
• Ochil and South Perthshire
• Ogmore
• Oldham West and Royton
• Pendle
• Penrith and The Border
• Perth and North Perthshire
• Preseli Pembrokeshire
• Pudsey
• Reading East
• Reading West
• Rhondda
• Richmond (Yorks)
• Rochford and Southend East
• Ross, Skye and Lochaber
• Rutherglen and Hamilton West
• Rutland and Melton
• Saffron Walden
• Salford and Eccles
• Sedgefield
• Selby and Ainsty
• Sherwood
• Shrewsbury and Atcham
• Solihull
• Somerton and Frome
• South East Cambridgeshire
• South Staffordshire
• South Swindon
• South Thanet
• South West Bedfordshire
• South West Surrey
• Southend West
• Stirling
• Stockton South
• Stone
• Streatham
• Swansea East
• Taunton Deane
• The Cotswolds
• Tiverton and Honiton
• Tonbridge and Malling
• Torridge and West Devon
• Totnes
• Vale of Clwyd
• Vauxhall
• Wakefield
• Walsall North
• Walsall South
• Wansbeck
• Wantage
• Warley
• Washington and Sunderland West
• Waveney
• Wealden
• Weaver Vale
• Wellingborough
• Wells
• Wentworth and Dearne
• West Bromwich East
• West Bromwich West
• West Ham
• Westminster North
• Wirral South
• Wolverhampton South West
• Workington
• Worsley and Eccles South
• Wyre and Preston North

Disappearing and newly created seats

Most of the new seats listed above are the result of name changes to existing constituencies following boundary changes of varying degrees, including five where the boundaries are unchanged. An existing seat where no part forms the largest part of any new seat is considered to be "disappearing". Conversely, any new seat which does not contain the largest part of any existing seat is considered to be genuinely "newly created".

The table below lists the disappearing and newly created constituencies.

Linked seats

An existing seat can be regarded as being linked to a newly named seat where part of the existing seat contributes the largest part of the newly named seat. 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. However, some arise from the consultation process and involve only minor changes. The table below lists those constituencies with name changes, indicating the extent of the changes by reference to the proportion of the old constituency included in the new constituency, or the proportion of the new in the old, which ever is the lesser:

• None – name change only
• Minor – greater than 90%
• Moderate – between 75% and 90%
• Major – between 50% and 75%
• Wholesale – less than 50%

Sources:

• Electoral Calculus – New Constituency Boundaries for 2023
• House of Commons Library – Boundary review 2023: Which seats will change in the UK?

Retained seats with major changes

The list below indicates those constituencies which have retained their names, but where boundary changes have resulted in major changes – where the proportion of the existing electorate included in the redefined constituency or vice versa, which ever is the lesser, is less than 75%.

• Aberdeen North
• Arundel and South Downs
• Ashford
• Ashton-under-Lyne
• Aylesbury
• Banbury
• Birmingham Ladywood
• Bishop Auckland
• Blackpool South
• Brentford and Isleworth
• Bridgend
• Bristol East
• Caithness, Sutherland and Easter Ross
• Cardiff South and Penarth
• Chippenham
• Dwyfor Meirionnydd
• East Hampshire
• Eastleigh
• Erith and Thamesmead
• Falkirk
• Glasgow East
• Glasgow North
• Glasgow North East
• Glasgow South West
• Gower
• Guildford
• Huntingdon
• Leeds North West
• Liverpool Riverside
• Liverpool Walton
• Liverpool Wavertree
• Liverpool West Derby
• Maidenhead
• Manchester Central
• Mid Sussex
• Milton Keynes North
• Morecambe and Lunesdale
• Newcastle upon Tyne North
• Newport East
• Northampton South
• Pontypridd
• Ribble Valley
• South Cambridgeshire
• South Norfolk
• South Northamptonshire
• South West Hertfordshire
• Stafford
• Stockport
• Stoke-on-Trent Central
• Stoke-on-Trent South
• Stourbridge
• Swansea West
• Westmorland and Lonsdale
• Windsor
• Wirral West
• Witney
• Wokingham
• Wolverhampton North East
• Wolverhampton South East
• Wrexham

Notional 2019 general election results

Researchers Michael Thrasher and Colin Rallings have calculated the notional results of the 2019 general election if it had taken place under the new constituency borders. In constituencies whose borders have changed, precise results under the new boundaries usually cannot be known as election results are not usually reported for subdivisions of constituencies. However, it is possible to estimate what the election results would have been by extrapolating from local election results for which more granular data is known.

Most news organisations, including the BBC, use these notional results for statistical purposes such as when calculating the swing from the 2019 general election to the 2024 general election by constituency.

The "Change" column is an index used by Thrasher and Rallings to refer to how radically the borders of the constituency in question changed in the boundary review. "None" is no change in the borders (therefore the notional results are identical to the actual results), a small number denotes little change, and a larger number denotes more change.

Great Britain

Northern Ireland

Precisely known results

Thanks to the City of Wolverhampton Council and Walsall Council deciding to publish results of the 2019 general election by ward, and the three new Wolverhampton constituencies not containing ward splits, the exact result of the election is known in those three seats. However, these results are not generally used by news organizations, which use Rallings and Thrasher's estimates nationwide.