New Boundaries 2023 Introduction

The current constituency boundaries have been in use since 2010. Neither of the two previous boundary reviews (in 2013 and 2018) have been adopted and implemented.

In a written statement in March 2020, the government announced that it is going to restart the stalled programme of new boundaries for Westminster constituencies. This new review will keep the number of seats at 650 and not reduce them to 600 as had been planned by David Cameron's coalition government.

But the next boundary review will require new seats to be nearly identical in terms of the number of electors in each seat. The review has a very strict limit, and requires each new seat to have an electorate which was not further than 5pc lower or higher than the average.

The previous legislation also specified that further new boundary reviews would take place every five years. This new act changes that period to every eight years, allowing for two Westminster elections to take place using each set of boundaries.

The current boundaries were first used in 2010 (and 2005 in Scotland), and are now getting a little out of date. Regular boundary reviews are an established part of the electoral process and a new review would be due around now in any case. The reviews are conducted by the four independent Boundary Commissions for England, Scotland, Wales and Northern Ireland and involve periods of public consultation.

This page contains description, analysis and predictions for the new 2023 boundaries as proposed by the four Boundary Commissions.

The Boundary Commissions published initial proposals between June and October 2021, with revised proposals in November 2022. Final proposals were published in June 2023.

The final proposals were approved by The Parliamentary Constituencies Order 2023 on 15 November 2023, and the new boundaries will be used at the next general election.

Summary by Area as at 2019

The table below shows the expected changes in the number of seats won by each party. This assumes that the General Election of 2019 was run again using the new boundaries and compares the hypothetical number of seats won by each party with the actual number. The numbers shown in the table are the change of seats.

On the intitial proposals, the Conservatives are set to benefit by around 13 seats, and Labour could lose eight seats. This is mainly due to seats moving out of Wales and the north of England and into the South.

England – Final proposals

In June 2023, the Boundary Commission for England published final proposals for the new English constituencies. The number of English seats has risen from 533 to 543. The estimated political breakdown of these seats is shown in the table below.

Party	Current Seats	New Seats	Change
CON	345	358	13
LAB	180	178	−2
LIB	7	6	−1
Green	1	1	0
Total	533	543	10

Electoral Calculus' calculations show the Conservatives gaining thirteen seats in England, while Labour loses two seats.

You can also see more details of the proposed new English seats on a regional basis: North East, North West, Yorks/Humber, West Midlands, East Midlands, Anglia, South West, London, South East.

Wales – Final proposals

On 28 June 2023, The Boundary Commission for Wales published final proposals for the new Welsh constituencies. The number of Welsh seats has fallen from 40 to 32. The estimated political breakdown of these seats is shown in the table below.

Party	Current Seats	New Seats	Change
CON	14	12	−2
LAB	22	18	−4
LIB	0	0	0
Plaid	4	2	−2
Total	40	32	−8

All the major parties lose some seats in Wales, due to the shrinking number of seats overall. Labour lose four seats, with the Conservatives and Plaid losing two seats each. But Labour is still predicted to have won over half the Welsh seats, mostly in south Wales.

You can also see more details of every proposed new seat in Wales.

Scotland – Final proposals

On 28 June 2023, The Boundary Commission for Scotland published final proposals for the new Scottish constituencies. The number of Scottish seats has fallen from 59 to 57. The estimated political breakdown of these seats is shown in the table below.

Party	Current Seats	New Seats	Change
CON	6	6	0
LAB	1	1	0
LIB	4	2	−2
SNP	48	48	0
Total	59	57	−2

There is not much change to Scotland as the majority of seats are still held by the SNP. The Liberal Democrats are at risk of losing two marginal seats which are expanding.

You can also see more details of every proposed new seat in Scotland.

Northern Ireland – Final proposals

On 28 June 2023, The Boundary Commission for Northern Ireland published final proposals for the new Northern Ireland constituencies. The number of Northern Ireland seats is unchanged at 18 and their political composition has not altered. The estimated political breakdown of these seats is shown in the table below.

Party	Current Seats	New Seats	Change
DUP	8	8	0
SF	7	7	0
SDLP	2	2	0
Alliance	1	1	0
Total	18	18	0

There is little change in Northern Ireland on the basis of these proposals.

You can also see more details of every proposed new seat in Northern Ireland.

UK – Final proposals

This analysis includes all the final proposals throughout the UK.

Disappearing seats

The following 24 seats are 'disappearing' in the sense that they are being broken up into pieces which will form the smaller part of new seats. The sitting MPs will have a political problem as there may not be a vacant winnable nearby seat.

Existing seat	Party	MP as at 2019	County (Area)
Arfon	Plaid	Hywel Williams	Gwynedd (Wales)
Blaydon	LAB	Liz Twist	Newcastle area (North East)
Brigg and Goole	CON	Andrew Percy	Humber area (Yorks/Humber)
Carmarthen West and Pembrokeshire South	CON	Simon Hart	Dyfed (Wales)
Clwyd South	CON	Simon Baynes	Clwyd (Wales)
Cynon Valley	LAB	Beth Winter	Mid Glamorgan (Wales)
Denton and Reddish	LAB	Andrew Gwynne	Eastern Manchester (North West)
Dudley South	CON	Mike Wood	Black Country (West Midlands)
Glasgow Central	SNP	Alison Thewliss	Glasgow area (Scotland)
Kingswood	CON	Chris Skidmore	Bristol area (South West)
Leeds West	LAB	Rachel Reeves	West Yorkshire (Yorks/Humber)
Meon Valley	CON	Flick Drummond	Hampshire (South East)
Newport West	LAB	Ruth Jones	Gwent (Wales)
Ogmore	LAB	Chris Elmore	Mid Glamorgan (Wales)
Penrith and The Border	CON	Neil Hudson	Cumbria (North West)
Ross Skye and Lochaber	SNP	Ian Blackford	Highland (Scotland)
Stone	CON	Bill Cash	Staffordshire (West Midlands)
Swansea East	LAB	Carolyn Harris	West Glamorgan (Wales)
Tyneside North	LAB	Mary Glindon	Newcastle area (North East)
Vale of Clwyd	CON	James Davies	Clwyd (Wales)
Walsall South	LAB	Valerie Vaz	Black Country (West Midlands)
Wiltshire North	CON	James Gray	Wiltshire (South West)
Wirral South	LAB	Alison McGovern	Merseyside (North West)
Wyre and Preston North	CON	Ben Wallace	Lancashire (North West)

Changing seats

The following 16 seats are expected to change politically due to the boundary changes and are likely to be lost by the incumbent party. Many of these new seats are quite marginal, so the sitting MP has a chance of being re-elected, but others are less close.

New seats

Due to population movements from the rest of the country into England, and from the north to the south of England, there are 24 seats which are newly created. These are defined as seats which don't contain the larger part of any existing seat. These seats are popular with prospective MPs as there is no natural incumbent.

New Seat	Party	Majority	County/Area
Bicester and Woodstock	CON	13,591	Oxfordshire (South East)
Bristol North East	LAB	7,801	Bristol area (South West)
Buckingham and Bletchley	CON	13,111	Buckinghamshire (South East)
Cheshire Mid	CON	3,604	Cheshire (North West)
Cotswolds North	CON	21,673	Gloucestershire (South West)
Earley and Woodley	CON	8,745	Berkshire (South East)
East Grinstead and Uckfield	CON	22,720	West Sussex (South East)
Frome and East Somerset	CON	15,471	Somerset (South West)
Godalming and Ash	CON	12,033	Surrey (South East)
Hamble Valley	CON	22,778	Hampshire (South East)
Harpenden and Berkhamsted	CON	14,145	Hertfordshire (Anglia)
Isle of Wight West	CON	11,751	Hampshire (South East)
Leeds West and Pudsey	LAB	5,231	West Yorkshire (Yorks/Humber)
Manchester Rusholme	LAB	27,492	Central Manchester (North West)
Melksham and Devizes	CON	15,190	Wiltshire (South West)
Melton and Syston	CON	20,153	Leicestershire (East Midlands)
St Neots and Mid Cambridgeshire	CON	12,842	Cambridgeshire (Anglia)
Stone, Great Wyrley and Penkridge	CON	21,716	Staffordshire (West Midlands)
Stratford and Bow	LAB	25,800	Newham (London)
Streatham and Croydon North	LAB	18,824	Lambeth (London)
Tiverton and Minehead	CON	20,613	Somerset (South West)
Wakefield and Rothwell	CON	2,268	West Yorkshire (Yorks/Humber)
Waveney Valley	CON	20,626	Suffolk (Anglia)
Weald of Kent	CON	27,316	Kent (South East)

Likely Political Impact estimated before official proposals

Electoral Calculus has made its own estimate of the political impact of these changes. This was done using both the latest ward electorate figures from 2020, combined with an Electoral Calculus algorithm to create an example set of new constituency boundaries. You can see full details of the estimates here.

Local Authority Ward Boundaries 2021+

The new legislation, the Parliamentary Constituencies Act 2019-21 (text) instructs the four Boundary Commissions (one each for England, Scotland, Wales and Northern Ireland) to conduct new parliamentary boundary reviews with a "review date" of 1 December 2020, and to complete the review before 1 July 2023.

The new parliamentary seats will be made up of, as much as possible, by joining together groups of (entire) local authority wards. This makes the local authority wards an important part of the new seat boundary process, so Electoral Calculus needs to use the same wards as the boundary commissions.

An innovation in the act is that the wards to be used are the "local government boundaries which exist, or are prospective, on the review date". This means that the wards used will be similar to the wards of 2020, but will include wards which will change in the next couple of years.

The Boundary Commission for England has interpreted the legislation to mean that they should use the English council wards as at 2021, but additionally to include the proposed new wards for some London boroughs.

Electoral Calculus electoral data has been upgraded to work with these wards of "2021+". These "Wards 2021+" are similar to the earlier "Wards 2019" which were incorporated in April 2020, but include changes to the following local authorities:

• Changed in 2020: Basingstoke and Deane, Buckinghamshire, Cambridge, Chorley, Halton, Hartlepool, Oxford, Pendle, Rotherham, Salford, Stroud.
• Changed in 2021: Cornwall, Isle of Wight, North Northamptonshire, West Northamptonshire, Wiltshire
• Proposed changes for 2022: Barnet, Brent, Camden, City of Westminster, Ealing, Enfield, Hammersmith And Fulham, Haringey, Harrow, Hillingdon, Hounslow, Islington, Lewisham, Merton, Richmond Upon Thames, Sutton

There are three new unitary authorities with replace several existing councils. These are shown in the table below.

New unitary authority	Previous district councils
Buckinghamshire	Aylesbury Vale Chiltern South Bucks Wycombe
North Northamptonshire	Corby East Northamptonshire Kettering Wellingborough
West Northamptonshire	Daventry Northampton South Northamptonshire

Over all the changes, there are a total of 841 new local authority wards.

The local election results from May 2021 for the newly created 2020 and 2021 wards have been included in the calculations. But there have never yet been elections for the new London wards, which will first be contested in 2022, so Electoral Calculus has used models to infer the likely result of earlier local elections in those new wards.

Using those data, it is possible to infer the likely result of the December 2019 general election in every ward of 2021+. This is necessary for analysing the Boundary Commissions proposals, in terms of predicting the political composition of each new seat.

History of revisions.

The data presented has been revised at various times.

• 27 April 2020 Initial version.
• 1 July 2020 New section on local authority wards 2020.
• 27 October 2020 Revised estimates of likely political impact
• 9 June 2021 Initial proposals for England
• 21 June 2021 Improved estimates for England initial proposals
• 29 June 2021 Added Map, Postcode lookup and regional pages
• 15 September 2021 Added initial analysis of new Welsh seats
• 14 October 2021 Added initial analysis of new Scottish seats
• 5 November 2021 Added initial analysis of new Northern Ireland seats
• 9 November 2022 Added revised proposals for England, Wales and Scotland
• 23 December 2022 Added revised proposals for Northern Ireland
• 4 July 2023 Added final proposals for all UK
• 3 January 2024 Confirmation that proposals have been adopted by Parliament for the next election

See also the information about the now-abandoned "2018 review", to compare against the 2023 Review.