Initial proposals for new constituency boundaries:

Standard Note: SN/SG/6195 Last updated: 23 January 2012

Authors: Feargal McGuinness Section Social and General Statistics

The number of parliamentary constituencies in Wales will fall from 40 to 30 as part of the current boundary review. Provisional proposals for the new seats were published by the Boundary Commission for Wales on 11 January 2012.

This note looks at the extent to which proposed constituencies can be identified with existing seats and which existing constituencies would be most affected by the proposals. The proposals for Wales are also compared with the initial proposals from the Boundary Commissions for England, Northern Ireland and Scotland, published in September and October 2011. Proposals for England, Scotland and Northern Ireland are analysed in detail in separate Library Standard Notes: SN06068 (England); SN06070 (Northern Ireland); SN06098 (Scotland).

Library Standard Note Constituency boundaries: the sixth general review discusses the background to the current review of constituency boundaries and also includes information on the public consultation that the Boundary Commissions must undertake. Library Standard Note Sizes of constituency electorates contains statistics on the electorate of existing constituencies, including regional variations and the deviation in electorate sizes from the UK Electoral Quota of 76,641.

This information is provided to Members of Parliament in support of their parliamentary duties and is not intended to address the specific circumstances of any particular individual. It should not be relied upon as being up to date; the law or policies may have changed since it was last updated; and it should not be relied upon as legal or professional advice or as a substitute for it. A suitably qualified professional should be consulted if specific advice or information is required.

This information is provided subject to our general terms and conditions which are available online or may be provided on request in hard copy. Authors are available to discuss the content of this briefing with Members and their staff, but not with the general public. Contents

1 Introduction 3 1.1 Reduction in seats 3 1.2 National Assembly for Wales 3

2 Extent of change 4 2.1 Changes to existing constituencies 4 2.2 Index of change 5 2.3 Map: Index of change, Wales 6

3 Local authority boundaries 7

4 Electorate size and deviation from electoral quota 8 4.1 Deviation from electoral quota 8 4.2 Largest and smallest electorates 8

5 Area of proposed constituencies 9

6 Partisan effect of the boundary changes 9

7 List of proposed constituencies 10 7.1 Map of existing and proposed constituency boundaries 11

8 Summary of initial proposals across the UK 12 8.1 Constituencies remaining unchanged 12 8.2 Electorate size 12 8.3 Geographical area 12 8.4 Extent of change 12 8.5 Map: Index of change, UK 13

2 1 Introduction The Boundary Commission for Wales published its initial proposals for 30 new Westminster parliamentary constituencies on 11 January 2012, as part of the Sixth Periodic Review of constituency boundaries.1

Generally the number of electors in any new constituency must be within 5% of the UK Electoral Quota of 76,641, based on the electorate at 1 December 2010, under the terms of the Parliamentary Voting System and Constituencies Act 2011. Therefore constituencies must contain no fewer than 72,810 electors and no more than 80,473 electors.2 The Boundary Commission for Wales has used electoral divisions as “the basic building block” in constructing its proposals, although in a small number of cases electoral divisions have been divided between proposed seats along the boundaries of communities.3

The Boundary Commission for Wales is required to make its final recommendations to the Government by October 2013 and, subject to Parliamentary approval, the final recommendations will be implemented at the next General Election. Maps of individual proposed constituencies can be downloaded from the Commission’s website.4

1.1 Reduction in seats Currently there are 40 constituencies in Wales, to be reduced to 30 as a result of the boundary review. The percentage reduction in the number of seats in Wales (25%) is at least twice as large as the percentage reduction in seats in Scotland, Northern Ireland and English regions. The review would mean that the average electorate of Welsh constituencies increases from about 57,000 to 76,000.

Table 1: Allocation of seats in boundary review

Number of existing Allocated number Reduction Mean electorate constituencies of constituencies in seats % c ha nge Before review After review UK 650 600 50 8% 70,530 76,408 England 533 502 31 6% 72,127 76,581 Scotland 59 52 7 12% 66,593 75,557 Wales 40 30 10 25% 57,040 76,053 Northern Ireland 18 16 2 11% 66,146 74,415

1.2 National Assembly for Wales National Assembly for Wales constituencies and regions are not included in the boundary review and the Boundary Commission for Wales’ proposals will introduce significant disparities between the boundaries of Westminster seats and Assembly constituencies. Currently Assembly constituencies are the same as Westminster parliamentary constituencies, but the Parliamentary Voting System and Constituencies Act 2011 removed the automatic link between the two sets of boundaries.5 The proposals mean that no National Assembly for Wales region would contain a whole number of Westminster seats.

1 http://www.bcomm-wales.gov.uk/2013_review_e.htm 2 The two Scottish island constituencies of Na h-Eileanan an Iar and Orkney and Shetland and two constituencies on the Isle of Wight are exempted from the requirements on electoral size. 3 Boundary Commission for Wales, 2013 Review of Constituency Boundaries: Initial Proposals, page 8 http://www.bcomm-wales.gov.uk/2013_review/initial_proposals_textonly_e.pdf 4 http://www.bcomm-wales.gov.uk/2013_review_maps_e.htm 5 http://www.legislation.gov.uk/ukpga/2011/1/pdfs/ukpga_20110001_en.pdf#page=18

3 2 Extent of change 2.1 Changes to existing constituencies Existing constituencies may be split up between several proposed seats. No constituency has been left unchanged in the proposals, but 15 out of 40 existing constituencies are wholly contained within proposed seats.

Chart 1: Division of existing seats into proposed seats Fraction of existing seat contained within a proposed seat

Wholly contained 15 in proposed seat

80-100% 7

60-80% 6

<60% 12

For two existing seats, there is no proposed constituency to which a majority of the existing seat’s electors have been transferred:

• South and Penarth has an electorate of 73,607, making it the only existing constituency in Wales to have an electorate within 5% of the UK Electoral Quota. 49% of its electors would be transferred to the proposed Cardiff Central and Penarth seat, 46% to the proposed Cardiff East seat, and 5% to The .

• The existing seat would be divided into three. 39% of its 52,216 electors would be added to the existing Rhondda seat to create a proposed enlarged Rhondda constituency. 37% of its electors would be added to the existing and Rhymney seat to create a new Heads of the Valleys constituency. The remaining 24% would be transferred to the proposed Pontypridd seat.

The existing constituency which contributes most electors to a proposed seat may be considered the ‘base’ constituency for the proposed seat. Eleven existing constituencies do not form the base for any proposed seat: Aberconwy; Arfon; Caerphilly; Cardiff Central; Carmarthen West and South ; Cynon Valley; Delyn; Gower; Montgomeryshire; Newport East; and Ogmore.

4 2.2 Index of change The extent to which boundaries are changed can be quantified by calculating an ‘index of change’. The index of change for a new constituency is equal to the number of electors being added to or removed from an existing base constituency, as a proportion of the base constituency’s total electorate.

Chart 2: Extent of change in constituency boundaries: Index of change

0-25 4

25-50 12 % Index of change 50-100 10

100+ 4

051015 Number of proposed constituencies

In four proposed constituencies the index of change exceeds 100%, meaning the number of electors leaving or joining the base is greater than the base electorate (in such cases the term ‘base’ is not very meaningful). These include Cardiff East and Cardiff Central and Penarth. The existing constituency which contributes most electors to both these seats is Cardiff South and Penarth.

These proposals represent a much more extensive revision of constituency boundaries than the boundary changes that came into force at the 2010 General Election. At the previous boundary review (which recommended the constituency boundaries currently in use), 18 out of 40 constituencies were left unchanged and in another 18 recommended seats the index of change was less than 10%, although in the north-west of Wales there was significant redrawing of boundaries.6

Index of change – Dee Estuary, example

The proposed Dee Estuary constituency has the existing Vale of seat as its base. 45,155 of Vale of Clwyd’s 56,264 electors are transferred to Dee Estuary, with

the remaining 11,109 electors in Vale of Clwyd transferred to another proposed constituency. Dee Estuary takes a further 35,123 electors from the existing Delyn seat.

The index of change for the proposed constituency is 82.2%: • Electorate of base = 56,264 • Electors removed from base = 11,109 • Electors added to base = 35,123 • Index of change = (11,109+35,123)/56,264 = 82.2%

6 Rallings and Thrasher, Media Guide to the New Parliamentary Constituencies, 2007

5 Proposed boundary changes: Index of change, Wales

Key: index of change 80 to 136 (10) 40 to 80 (9) 20 to 40 (9) 0to 20 (2)

© Crown copyright. All rights reserved. House of Commons Library (OS) 100040654 and (OSNI) 2085 (2012) 3 Local authority boundaries 14 proposed constituencies are wholly contained within a single unitary authority. There are 16 proposed seats, listed in Table 1, which contain parts of at least two unitary authorities.

Six unitary authorities contain fewer than 72,810 electors (the minimum number of electors permitted in any proposed constituency); each is wholly contained within a proposed seat. unitary authority is split between two proposed constituencies, although its electorate of 74,416 is within 5% of the UK Electoral Quota.

The requirement on electorate size means that in some areas the Commission has proposed constituencies which cross historic boundaries. In particular, the current island constituency of Ynys Môn has an electorate of 49,524, which is well outside the permitted range. Therefore the Commission proposes combining Ynys Môn with parts of and Conwy unitary authorities. The proposed Llanelli constituency straddles the River Loughor, which separates Carmarthenshire and Swansea unitary authorities. The proposed Aberavon and Ogmore constituency crosses the boundary between the preserved counties of and . The Commission also proposes combining parts of Cardiff and Caerphilly unitary authorities to create a Caerphilly and Cardiff North seat.

Table 2: Proposed constituencies crossing unitary authority boundaries

Proposed constituency Relevant unitary authorities

Glyndwr and North Denbighshire Powys Conwy and North Pembrokeshire Ceredigion * Pembrokeshire Carmarthenshire Gwynedd Gwynedd Conwy Powys Heads of the Valleys Merthyr Tydfil * Rhondda Cynon Taf Caerphilly Menai ac Ynys Môn Isle of * Gwynedd Conwy

Aberavon and Ogmore Neath Port Talbot Bridgend Blaenau * Caerphilly Caerphilly and Cardiff North Cardiff Caerphilly Cardiff Central and Penarth Cardiff The Vale of Glamorgan Cardiff West Cardiff Rhondda Cynon Taf

Dee Estuary Denbighshire Llanelli Carmarthenshire Swansea Monmouthshire Monmouthshire * Newport Neath Neath Port Talbot Swansea Newport West and Sirhowy Valley Caerphilly Newport Torfaen * Newport

* Unitary authority wholly contained within proposed constituency

In general the Commission has constructed proposed constituencies from whole electoral divisions. However in four cases the proposals involve splitting electoral divisions and the boundaries of communities are followed instead.

The proposed Glyndwr and North Powys seat involves splitting three electoral divisions. It would take a small number of electors from Tremeirchion in the County of Denbighshire, with the rest of the electoral division contained in the proposed Dee Estuary constituency. The electoral divisions of Ponciau and of Penycae and Ruabon South, both in the County Borough of Wrexham, would be part contained in Glyndwr and North Powys and part contained in the proposed seat of Wrexham .

Llansamlet ward in the City and County of Swansea is split between the proposed Neath constituency and the proposed Swansea East constituency.

7 4 Electorate size and deviation from electoral quota 4.1 Deviation from electoral quota The Boundary Commission for Wales is required to propose constituencies that have an electorate within 5% of the UK Electoral Quota of 76,641. Therefore constituency electorates must be at least 72,810 and at most 80,473. The average electorate of the 30 proposed seats in Wales is 76,053, about 600 electors (0.8%) fewer than the quota. Therefore the electorates of proposed seats are skewed towards the bottom end of the permitted electorate range, as shown in Chart 3.

Chart 3: Deviation of proposed constituency electorates from UK Electoral Quota

-5%-4%-3%-2%-1%0%1%2%3%4%5% % deviation from quota

4.2 Largest and smallest electorates The proposed constituency with the largest electorate is Dee Estuary, which contained 80,278 electors at 1 December 2010. It comprises 80% of the existing Vale of Clwyd seat and 65% of the existing Delyn seat.

The only other proposed seat to contain more than 80,000 electors is Alyn and Deeside, which has an electorate of 80,268. It wholly contains the existing constituency of the same name, as well as 35% of the electorate of the existing Delyn seat.

The proposed constituency with the smallest electorate is Rhondda, which has an electorate of 73,194 and wholly contains the existing Rhondda seat.

Currently the largest seat in Wales in electoral terms is Cardiff South and Penarth, which has an electorate of 73,607. The smallest existing seat is Arfon, with an electorate of 40,707.

8 5 Area of proposed constituencies The proposals mean that the median area of Welsh constituencies would increase by about 40%. The median area of the 30 proposed seats is 276 km2, compared to 195 km2 for the 40 current constituencies.

The proposed South Powys constituency has an area of 3,898 km2. South Powys would wholly contain the existing Brecon and Radnorshire seat, which is currently the largest in Wales with an area of 3,015 km2. Currently there are seven constituencies in Wales in excess of 1,000 km2, listed in Table 3. These seven existing seats would be wholly contained within the six largest proposed seats.

Table 3: Existing and proposed constituencies with an area in excess of 1,000 km2

Existing constituency Area (km2) Proposed constituency Area (km2) Brecon and Radnorshire 3,015 South Powys 3,898 2,185 Gwynedd 3,160 Montgomeryshire 2,182 Ceredigion and North Pembrokeshire 2,461 Ceredigion 1,806 Glyndwr and North Powys 2,199 Carmarthen East and Dinefwr 1,561 Caerfyrddin 2,116 1,193 South and West Pembrokeshire 1,042 Carmarthen West and Pembrokeshire South 1,059

Source: Ordnance Survey, Boundary Commission for Wales

6 Partisan effect of the boundary changes There are no official figures for what the results of the 2010 General Election would have been if the proposed new constituency areas had been used. Some unofficial estimates have, however, already been made. Anthony Wells of UK Polling Report estimates that if votes cast in the 2010 General Election had been counted on the proposed boundaries, Labour would have won 20 seats in Wales compared to the 26 they currently hold. The Conservatives would have won 6 seats (down from 8), the Liberal Democrats 2 seats (down from 3) and Plaid Cymru 2 seats (down from 3).7

One method of estimating notional results uses votes cast at the most recent local elections to estimate voting patterns at the General Election. The 2010 General Election result in an old base constituency is adjusted to take account of the votes in the local elections in the electoral divisions it is gaining or losing. To votes cast in the 2010 General Election in the old constituency is added or subtracted the estimated number of the votes that each of the major parties received in those electoral divisions at the General Election. The number of votes in the relevant electoral divisions is estimated from the distribution of votes cast for each of the main parties across all the electoral divisions making up the former constituency, at the 2008 local elections. This is an attempt to reflect the relative party strength in electoral divisions gained or lost.

This is roughly the same method used by Michael Thrasher and Colin Rallings of the Local Government Elections Centre at the University of Plymouth,8 who have produced notional general election results for previous boundary reviews. Thrasher and Rallings are not producing notional results for the new constituencies until they are finalised.

7 http://ukpollingreport.co.uk/blog/archives/4627 8 http://www.plymouth.ac.uk/pages/view.asp?page=16182

9 7 List of proposed constituencies

Index of Proposed constituency Electorate Rank Area (km2)Rank change Aberavon and Ogmore 73,895 24 279.3 15 71.8 Alyn and Deeside 80,268 2 214.0 18 30.5 Blaenau Gwent 77,304 9 157.5 21 44.4 Bridgend 73,596 27 143.3 22 24.9 Caerfyrddin 76,549 14 2,116.4 5 47.3 Caerphilly and Cardiff North 73,873 25 101.5 26 98.1 Cardiff Central and Penarth 76,346 16 30.0 30 105.2 Cardiff East 79,287 3 48.4 29 115.9 Cardiff West 74,844 18 64.8 27 18.1 Ceredigion and North Pembrokeshire 74,173 22 2,460.9 3 32.4 Dee Estuary 80,278 1 392.0 9 82.2 Glyndwr and North Powys 74,554 20 2,199.3 4 135.8 Gower and Swansea West 77,453 8 242.0 17 92.2 Gwynedd 73,297 28 3,160.1 2 63.6 Heads of the Valleys 74,029 23 273.2 16 35.2 Llanelli 76,970 10 326.3 14 31.7 Menai ac Ynys Môn 74,453 21 981.5 7 50.3 Monmouthshire 73,862 26 916.5 8 38.4 Neath 76,747 11 350.8 12 33.2 Newport Central 76,461 15 105.7 25 99.1 Newport West and Sirhowy Valley 73,217 29 171.2 19 121.2 North Wales Coast 78,628 4 360.6 10 89.6 Pontypridd 77,786 7 164.9 20 48.1 Rhondda 73,194 30 137.0 24 38.7 South and West Pembrokeshire 76,039 17 1,041.7 6 88.0 South Powys 78,136 6 3,897.8 1 45.7 Swansea East 76,637 13 62.7 28 42.8 The Vale of Glamorgan 74,728 19 330.1 13 5.0 Torfaen 76,639 12 140.7 23 24.3 78,353 5 354.5 11 51.6

Source: Boundary Commission for Wales

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8 Summary of initial proposals across the UK The publication of proposals for Wales means that initial proposals for new constituency boundaries have now been published for the whole of the UK. Across the UK the number of constituencies will fall from 650 to 600 as a result of the boundary review. The average constituency electorate (excluding exempted constituencies9) will increase by about 6,000.

8.1 Constituencies remaining unchanged 80 constituencies are left intact in the initial proposals, 77 in England and 3 in Scotland. These include the two island constituencies of Na h-Eileanan an Iar and Orkney and Shetland. Additionally Basingstoke constituency would see a slight realignment of its boundaries but its electorate would be unaffected.

8.2 Electorate size The proposed Hackney North seat in London contains the maximum permitted number of electors (80,473) and so is the largest proposed constituency in electoral terms.

The seats with the smallest electorates are the preserved constituencies of Na h-Eileanan an Iar and Orkney and Shetland, containing 21,837 electors and 33,755 electors respectively. The proposed Isle of Wight South seat has an electorate of 54,671 and would be the smallest seat in England, followed by Isle of Wight North which has an electorate of 56,253. Out of the 596 seats not exempted from requirements on electoral size, the proposed Oldham and Saddleworth constituency has the minimum permitted electorate of 72,810.

8.3 Geographical area The Boundary Commission for Scotland’s proposals include a Caithness, Sutherland, Ross and Cromarty seat with an area of 12,830 km2 and an electorate of 74,290. The largest existing constituency, Ross, Skye and Lochaber, is slightly smaller at 12,779 km2 but contains over 20,000 fewer electors.

The six largest proposed constituencies are all in Scotland. South Powys in Wales is the seventh largest with an area of 3,898 km2. The proposed Fermanagh and South Tyrone seat (2,940 km2) is the largest in Northern Ireland and the 13th largest of all proposed UK seats. England’s largest proposed seat, Hexham (2,604 km2), is the 16th largest overall.

8.4 Extent of change 44 proposed seats have an index of change greater than 100%, so that the number of electors transferred to or from some existing base constituency in order to create the proposed seat is greater than the base constituency’s electorate. These include 37 proposed seats in England, 4 in Wales and 3 in Scotland.

Seats proposed by the Boundary Commission for Wales have an average index of change of 60%. This is higher than for any other part of the UK. The average index of change for proposed North East England constituencies and for proposed London seats is 59%.

The region with the lowest average index of change is South East England (27%). There are currently 84 constituencies in the South East and the region would lose one seat in the boundary review. By contrast, Wales contains 40 seats currently and will lose 10.

9 Na h-Eileanan an Iar, Orkney and Shetland, and two seats on the Isle of Wight.

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