Following the passage of the Parliamentary Voting System and Constituencies Act, the four national Boundary Commissions were asked to undertake the "2018 Review" of contituency boundaries to equalise the size of seat both within and between the four nations of the UK. The Boundary Commissions are independent bodies who put considerable effort into drawing up boundaries in a generally fair way, reflecting local geography and affiliations. There are two consultation periods where comments and objections to the proposals can be brought forward for consideration.
The Boundary Commission of England published its initial set of proposals on 13 September 2016, with final proposals being ready by September 2018. The Welsh Boundary Commission also published their initial proposals on the same day. The Boundary Commission for Northern Ireland published its initial proposals on 6 September 2016. The Scottish Boundary Commission is published its initial proposals on 20 October 2016.
Click on the map image to go to a full browsable map of the all the seats with initial proposals.
Press reports in early September 2017 (see Times or Guardian) suggest that the government is unlikely to push forward with the reduction in seats to 600. It is suggested that the Boundary Commissions will be asked to repeat their reviews but keeping the total number of seats at 650.
That will require primary legislation, since the 600 seats are set down in the Parliamentary Voting System and Constituencies Act 2011. If new legislation is brought forward it could usefully also change the electorate tolerances from 5pc to 10pc, as this would make seats more homogeneous and reduce the need to cross traditional boundaries.
A repeat of the reviews could not be done very quickly, since all the proposed boundaries would have to be redrawn and the consultation processes re-run on the new boundaries.
Taken together, this greatly increases the chances that the next general election will be run under the existing boundaries.
The total number of seats per consituent part of the country is already known:
|Area||Old Seats||New Seats||Change|
This page contains full details of these reviews as they are published.
The Boundary Commissions have now all published their initial proposals. This allows us to get a good overall view of the likely outcome. In terms of the headline impact on seats nationally the implied result of the 2017 general election, as if it had been run under the new boundaries, is:
election result 2017
|Implied result at 2017|
under new boundaries
|Change||Disappear||Switch Out||Switch In||Fresh|
The Conservatives would change from being 8 seats short of a majority to being 3 seats short. The DUP fall from ten seats to seven, so the combined Conservative/DUP bloc would increase its majority slightly from six to ten.
The analysis below shows which seats "disappear" under the boundary changes, which seats switch party allegiance, and which fresh seats are newly created.
Area by area, the net change in seats is shown in this table:
|Region||Old Seats||New Seats||Change||CON||LAB||LIB||UKIP||Green||NAT||MIN|
There are full regional pages of explanation and seat breakdowns available. Just click on the region's name in the left-hand column of the table.
Generally, the regions of northern England and London lose the most seats, while southern England loses fewer seats. Since the former regions are more Labour-leaning than the latter, this is the main driver for the relatively larger losses of Labour seats.
For each proposed new seat, we define the predecessor seat to be the old seat which contributes the most voters to that new seat. Old seats which are not the predecessor of any new seat are said to "disappear". This means that they are split into fragments, and none of those fragments forms the largest part of any new seat.
There are 59 disappearing seats across the country, shown in the table below:
|Old Seat||Party||Current MP||County/Area|
|Aberavon||LAB||Stephen Kinnock||West Glamorgan (Wales)|
|Aberconwy||CON||Guto Bebb||Clwyd (Wales)|
|Angus||CON||Kirstene Hair||Tayside (Scotland)|
|Arfon||Plaid||Hywel Williams||Gwynedd (Wales)|
|Ayrshire Central||SNP||Philippa Whitford||Ayrshire and Lanark (Scotland)|
|Belfast South||DUP||Emma Little Pengelly||Antrim (Northern Ireland)|
|Birmingham Hall Green||LAB||Roger Godsiff||Birmingham (West Midlands)|
|Bournemouth West||CON||Conor Burns||Dorset (South West)|
|Bradford South||LAB||Judith Cummins||West Yorkshire (Yorks/Humber)|
|Cardiff Central||LAB||Jo Stevens||South Glamorgan (Wales)|
|Carmarthen West and Pembrokeshire South||CON||Simon Hart||Dyfed (Wales)|
|Chelsea and Fulham||CON||Greg Hands||Hammersmith and Fulham (London)|
|Cornwall North||CON||Scott Mann||Cornwall (South West)|
|Delyn||LAB||David Hanson||Clwyd (Wales)|
|Derbyshire North East||CON||Lee Rowley||Derbyshire (East Midlands)|
|Dudley North||LAB||Ian Austin||Black Country (West Midlands)|
|Edinburgh South||LAB||Ian Murray||Edinburgh area (Scotland)|
|Enfield Southgate||LAB||Bambos Charalambous||Enfield (London)|
|Faversham and Kent Mid||CON||Helen Whately||Kent (South East)|
|Gedling||LAB||Vernon Coaker||Nottinghamshire (East Midlands)|
|Glasgow North||SNP||Patrick Grady||Glasgow area (Scotland)|
|Gower||LAB||Tonia Antoniazzi||West Glamorgan (Wales)|
|Great Grimsby||LAB||Melanie Onn||Humber area (Yorks/Humber)|
|Hackney North and Stoke Newington||LAB||Diane Abbott||Hackney (London)|
|Haltemprice and Howden||CON||David Davis||Humber area (Yorks/Humber)|
|Herefordshire North||CON||Bill Wiggin||Hereford and Worcestershire (West Midlands)|
|Houghton and Sunderland South||LAB||Bridget Phillipson||Newcastle area (North East)|
|Ilford South||LAB||Mike Gapes||Redbridge (London)|
|Islwyn||LAB||Chris Evans||Gwent (Wales)|
|Kenilworth and Southam||CON||Jeremy Wright||Warwickshire (West Midlands)|
|Kirkcaldy and Cowdenbeath||LAB||Lesley Laird||Fife (Scotland)|
|Lancaster and Fleetwood||LAB||Cat Smith||Lancashire (North West)|
|Leeds West||LAB||Rachel Reeves||West Yorkshire (Yorks/Humber)|
|Lewisham Deptford||LAB||Vicky Foxcroft||Lewisham (London)|
|Lewisham West and Penge||LAB||Ellie Reeves||Lewisham (London)|
|Liverpool Walton||LAB||Dan Carden||Merseyside (North West)|
|Meon Valley||CON||George Hollingbery||Hampshire (South East)|
|Middlesbrough||LAB||Andy McDonald||Teesside (North East)|
|Mitcham and Morden||LAB||Siobhain McDonagh||Merton (London)|
|Montgomeryshire||CON||Glyn Davies||Powys (Wales)|
|Motherwell and Wishaw||SNP||Marion Fellows||Glasgow area (Scotland)|
|Newcastle upon Tyne Central||LAB||Chi Onwurah||Newcastle area (North East)|
|Newport East||LAB||Jessica Morden||Gwent (Wales)|
|Oldham East and Saddleworth||LAB||Debbie Abrahams||Eastern Manchester (North West)|
|Pendle||CON||Andrew Stephenson||Lancashire (North West)|
|Penistone and Stocksbridge||LAB||Angela Smith||South Yorkshire (Yorks/Humber)|
|Pontypridd||LAB||Owen Smith||Mid Glamorgan (Wales)|
|Ross Skye and Lochaber||SNP||Ian Blackford||Highland (Scotland)|
|Stirling||CON||Stephen Kerr||Central (Scotland)|
|Stockport||LAB||Ann Coffey||Eastern Manchester (North West)|
|Stockton North||LAB||Alex Cunningham||Teesside (North East)|
|Stoke-on-Trent Central||LAB||Gareth Snell||Staffordshire (West Midlands)|
|Tatton||CON||Esther McVey||Cheshire (North West)|
|Ulster Mid||SF||Francie Molloy||Tyrone (Northern Ireland)|
|Walsall North||CON||Eddie Hughes||Black Country (West Midlands)|
|Wansbeck||LAB||Ian Lavery||Northumberland (North East)|
|Wirral South||LAB||Alison McGovern||Merseyside (North West)|
|Witham||CON||Priti Patel||Essex (Anglia)|
|Workington||LAB||Sue Hayman||Cumbria (North West)|
If an MP's name is shown here it does not mean that he or she will stop being an MP at the next election. But they have to change the precise area which they represent, and they may be subject to their party's reselection process.
Some new seats have clear predecessor seats, but the boundary changes are large enough that the new seat contains many voters with a different political outlook. This can cause the new seat to have a different predicted party winner from its predecessor. Such seats are called "switching seats", and there are 50 of them:
|Current MP||New seat||New Party||New|
|Airdrie and Shotts||SNP||Neil Gray||Airdrie South and Shotts||LAB||505||Glasgow area (Scotland)|
|Barrow and Furness||LAB||John Woodcock||Barrow and Furness||CON||1,269||Cumbria (North West)|
|Belfast North||DUP||Nigel Dodds||Belfast North West||SF||2,869||Antrim (Northern Ireland)|
|Bolton West||CON||Chris Green||Bolton West||LAB||2,043||Western Manchester (North West)|
|Brighton Kemptown||LAB||Lloyd Russell-Moyle||Brighton East and Newhaven||CON||3,000||East Sussex (South East)|
|Brighton Pavilion||Green||Caroline Lucas||Brighton North||LAB||2,782||East Sussex (South East)|
|Caithness Sutherland and Easter Ross||LIB||Jamie Stone||Highland North||SNP||1,044||Highland (Scotland)|
|Calder Valley||CON||Craig Whittaker||Calder Valley||LAB||1,888||West Yorkshire (Yorks/Humber)|
|Camborne and Redruth||CON||George Eustice||Falmouth and Camborne||LAB||3||Cornwall (South West)|
|Canterbury||LAB||Rosie Duffield||Canterbury and Faversham||CON||2,049||Kent (South East)|
|Carmarthen East and Dinefwr||Plaid||Jonathan Edwards||Carmarthenshire||LAB||622||Dyfed (Wales)|
|Carshalton and Wallington||LIB||Tom Brake||Carshalton and Wallington||CON||739||Sutton (London)|
|Cheadle||CON||Mary Robinson||Stockport South and Cheadle||LAB||590||Eastern Manchester (North West)|
|Chingford and Woodford Green||CON||Iain Duncan Smith||Chingford and Woodford Green||LAB||1,402||Waltham Forest (London)|
|Cities of London and Westminster||CON||Mark Field||Cities of London and Westminster||LAB||834||City of Westminster (London)|
|Clwyd South||LAB||Susan Elan Jones||Clwyd South and Montgomeryshire North||CON||3,222||Clwyd (Wales)|
|Copeland||CON||Trudy Harrison||Workington and Whitehaven||LAB||10,371||Cumbria (North West)|
|Coventry North West||LAB||Geoffrey Robinson||Coventry West and Meriden||CON||4,736||Coventry and Solihull (West Midlands)|
|Derby South||LAB||Margaret Beckett||Derby South||CON||1,287||Derbyshire (East Midlands)|
|Dwyfor Meirionnydd||Plaid||Liz Roberts||Clwyd North and Gwynedd||CON||392||Gwynedd (Wales)|
|Edinburgh East||SNP||Tommy Sheppard||Edinburgh East||LAB||6,087||Edinburgh area (Scotland)|
|Edinburgh South West||SNP||Joanna Cherry||Edinburgh South West and Central||LAB||775||Edinburgh area (Scotland)|
|Edinburgh West||LIB||Christine Jardine||Edinburgh West||SNP||1,704||Edinburgh area (Scotland)|
|Finchley and Golders Green||CON||Mike Freer||Finchley and Southgate||LAB||7,600||Barnet (London)|
|Glasgow East||SNP||David Linden||Glasgow East||LAB||99||Glasgow area (Scotland)|
|Halesowen and Rowley Regis||CON||James Morris||Birmingham Selly Oak and Halesowen||LAB||4,099||Birmingham (West Midlands)|
|Harrow East||CON||Bob Blackman||Kenton||LAB||5,203||Harrow (London)|
|Keighley||LAB||John Grogan||Keighley||CON||1,522||West Yorkshire (Yorks/Humber)|
|Kensington||LAB||Emma Dent Coad||Kensington and Chelsea||CON||5,110||Kensington and Chelsea (London)|
|Lincoln||LAB||Karen Lee||Lincoln||CON||140||Lincolnshire (East Midlands)|
|Londonderry East||DUP||Gregory Campbell||Glenshane||SF||2,549||Londonderry (Northern Ireland)|
|Midlothian||LAB||Danielle Rowley||Midlothian and Peebles||SNP||1,085||Edinburgh area (Scotland)|
|Morecambe and Lunesdale||CON||David Morris||Lancaster and Morecambe||LAB||6,446||Lancashire (North West)|
|Morley and Outwood||CON||Andrea Jenkyns||Batley and Morley||LAB||4,804||West Yorkshire (Yorks/Humber)|
|Norwich North||CON||Chloe Smith||Norwich North||LAB||1,979||Norfolk (Anglia)|
|Ochil and South Perthshire||CON||Luke Graham||Clackmannanshire and Stirling North||SNP||1,740||Central (Scotland)|
|Oxford West and Abingdon||LIB||Layla Moran||Oxford West and Abingdon||CON||2,411||Oxfordshire (South East)|
|Pudsey||CON||Stuart Andrew||Pudsey||LAB||12,356||West Yorkshire (Yorks/Humber)|
|Southampton Itchen||CON||Royston Smith||Southampton Itchen||LAB||3,337||Hampshire (South East)|
|Stoke-on-Trent South||CON||Jack Brereton||Stoke-on-Trent South||LAB||2,850||Staffordshire (West Midlands)|
|Stroud||LAB||David Drew||Stroud||CON||632||Gloucestershire (South West)|
|Telford||CON||Lucy Allan||Telford||LAB||1,027||Shropshire (West Midlands)|
|Upper Bann||DUP||David Simpson||Upper Bann and Blackwater||SF||5,379||Armagh (Northern Ireland)|
|Uxbridge and South Ruislip||CON||Boris Johnson||Hillingdon and Uxbridge||LAB||1,073||Hillingdon (London)|
|Vale of Glamorgan||CON||Alun Cairns||Vale of Glamorgan East||LAB||714||South Glamorgan (Wales)|
|Warwick and Leamington||LAB||Matt Western||Kenilworth and Leamington||CON||5,249||Warwickshire (West Midlands)|
|Watford||CON||Richard Harrington||Watford||LAB||616||Hertfordshire (Anglia)|
|Weaver Vale||LAB||Mike Amesbury||Weaver Vale||CON||6,831||Cheshire (North West)|
|Westmorland and Lonsdale||LIB||Tim Farron||Westmorland and Lonsdale||CON||2,316||Cumbria (North West)|
|Wimbledon||CON||Stephen Hammond||Merton and Wimbledon Central||LAB||5,793||Merton (London)|
Notable seats changing hands include many Conservative losses such as the Cities of London and Westminster, the recent by-election gain in Copeland, Ed Balls' old seat of Morley and Outwood, and Norwich North. The Conservatives are slated to regain Kensington
Although the overall change is to reduce the number of seats, there are a few new seats which are freshly created. This means that the new seat is made up of a number of small fragments from various old seats. If the largest component of the new seat is not the largest part of its corresponding old seat, then the seat is defined to be "fresh". There are nine fresh new seats:
|Bramhall and Poynton||CON||14,343||Eastern Manchester (North West)|
|Down West||DUP||14,063||Armagh (Northern Ireland)|
|Forest Gate and Loxford||LAB||38,748||Newham (London)|
|Grimsby North and Barton||CON||6,578||Humber area (Yorks/Humber)|
|Isle of Wight West||CON||11,365||Hampshire (South East)|
|Kinross-shire and Cowdenbeath||CON||2,340||Fife (Scotland)|
|Middlesbrough West and Stockton East||LAB||12,612||Teesside (North East)|
|Peckham and Lewisham West||LAB||32,781||Lewisham (London)|
The Boundary Commission for England published initial proposals on 13 September 2016.
The net effect of the changes for England is shown in the following table:
|Old Seats||New Seats||Change||Disappear||Switch Out||Switch In||Fresh|
Full details are available on the area pages: North East, North West, Yorks/Humber, West Midlands, East Midlands, Anglia, South West, London, South East
The Boundary Commission for Wales published initial proposals on 13 September 2016.
The net effect of the changes for Wales is shown in the following table:
|Old Seats||New Seats||Change||Disappear||Switch Out||Switch In||Fresh|
Visit the Wales Area page for more details.
The Boundary Commission for Scotland published its initial proposals on 20 October 2016.
The net effect of the changes for Scotland is shown in the following table:
|Old Seats||New Seats||Change||Disappear||Switch Out||Switch In||Fresh|
Visit the Scotland Area page for more details.
New parliamentary boundaries were announced on 6 September by the Boundary Commission for Northern Ireland. Analysis of these initial proposals by Electoral Calculus, assuming that voting patterns remain stable, indicates the the Democratic Unionist Party may lose three of its ten Westminster seats, and that the republican Sinn Féin is likely to gain two seats to become the largest party in Northern Ireland. The total number of seats in the province decreases from 18 to 17.
Other changes include the dismemberment into fragments of Belfast South (DUP), and Ulster Mid (SF), which effectively disappear as seats. But Sinn Féin more than compensates for this by taking three seats from the DUP. These are Belfast North (renamed 'Belfast North West'), Upper Bann (renamed 'Upper Bann and Blackwater'), and Londonderry East (renamed 'Glenshane'). There is also one new seat created called Down West, which is predicted to be won by the DUP.
|Party||Old Seats||New Seats||Change||Commentary|
|DUP||10||7||−3||Lose Belfast South (disappears), Belfast North,
Londonderry East, and Upper Bann;
and gain Down West (new seat)
Belfast North West,
Upper Bann and Blackwater; lose Ulster Mid (disappears)
|MIN||1||1||0||Hold Down North|
Visit the Northern Ireland Area page for more details.
The seat detail pages now have the new local election results, and updated local ward boundaries where they have changed. This major data upgrade shows clearly the interplay between recent national and local elections, as well as showing more details about the political make-up of each constituency.
You can see these new seat details by going to the index pages on the left-hand menu bar (England A-B, ..., Wales, Scotland, Northern Ireland), or by using the postcode lookup for any UK location:
An example seat is Arundel and South Downs (BN14 0TF) which has had updated boundaries.
Results include the following parties shown separately:
Local election results used are now:
Since 2010, sixty-two English councils have been given new boundaries by the Local Government Boundary Commission for England (LGBCE), and these new boundaries took effect at the 2015 elections. These new ward boundaries are now included for both the results drilldown and the accompanying maps.
In Northern Ireland, there has been a substantial redrawing of boundaries. There are now 11 district councils, with 462 wards which are grouped into 80 District Electoral Areas (DEAs). The NI local elections were conducted in 2014 using the DEAs, so Northern Ireland mapping and analysis is based on the DEAs rather than the actual wards. Please note that NI mapping data is difficult to obtain freely, so some boundaries may be slightly approximate.
It is expected that the Boundary Commissions will redraw parliamentary constituencies starting from Spring 2016 and using these 2015 local ward boundaries as their basic building blocks.
See also the information about the now-abandonned "Sixth Periodic review", to compare against the 2018 Review.