| Senedd constituencies and electoral regions | |
|---|---|
| |
 Map of the 40 constituencies (left side) and the 5 electoral regions (right side) of the Senedd in Wales | |
| Category | Electoral district |
| Location | Wales |
| Created by | Government of Wales Act 1998 |
| Created |
|
| Number | 40 constituencies 5 regions[a] (as of 2021) |
| Populations | Constituency: 43,125 (Arfon) - 81,366 (Cardiff South and Penarth) Region: 413,569 (South Wales West) - 523,096 (South Wales Central) |
| Government | |
TheSenedd constituencies and electoral regions (Welsh:Etholaethau a Rhanbarthau etholiadol Senedd Cymru)[i] are the electoral districts used to electmembers of the Senedd (MS;Welsh:Aelodau'r Senedd or AS) to theSenedd (Welsh Parliament;Welsh:Senedd Cymru), and have been used in some form since the first election of the thenNational Assembly for Walesin 1999.
There are currently forty single-member constituencies and five four-member regions. The five electoral regions are:Mid and West Wales,North Wales,South Wales Central,South Wales East, andSouth Wales West, with the forty constituencies listed below.[4]Voting last took place in all districts in the2021 Senedd election, and is not used forlocal government. The current boundaries were introduced for the2007 Assembly election.
The constituencies were created through theGovernment of Wales Act 1998, which established the National Assembly for Wales. The Assembly's constituencies were initially linked to the boundaries used forUK Parliament constituencies in Wales, set by theUK Parliament'sBoundary Commission for Wales, except a delay in implementing new boundaries between the 2007 Assembly election and the subsequent2010 UK election. TheParliamentary Voting System and Constituencies Act 2011, unlinked the two sets of constituencies, meaning any changes to one set, no longer affected the other. Subsequently, the UK Parliamentintroduced new constituencies for its2024 UK election, and theDemocracy and Boundary Commission Cymru was set up in 2024 to conduct boundary reviews of Senedd constituencies, with the constituencies not been overseen by a statutory body prior to 2024.[5]
As part ofSenedd reforms, new boundaries will be introduced for the2026 Senedd election followinga boundary review, consisting ofsixteen six-member constituencies with Welsh-only names, while the electoral regions are being abolished. Another review will be conducted for the 2030 election.
Following the1997 Welsh devolution referendum, where a narrow majority voted in support of the creation of adevolvedWelsh Assembly, constituencies of the devolved legislature were established.
Section 2 of theGovernment of Wales Act 1998 stipulates that the constituencies for theNational Assembly for Wales be the same as the constituencies used for elections to theUnited Kingdom Parliament.[6] The same act sets out the creation of five regions which would use the same borders as the fiveEuropean Parliamentary constituencies in Wales which themselves were set out in the European Parliamentary Constituencies (Wales) Order 1994,[7] used forelections to theEuropean Parliament between1994 and1999. The electoral regions set out are still used, despite the abolishment of the five European Parliamentary constituencies for anall-Wales constituency, and the withdrawal of theUK from theEuropean Union. Although minor border adjustments to the regions have taken place.
In 2006, theGovernment of Wales Act 2006 was enacted. When enacted the act reinforced the link between Assembly and UK Parliamentary constituencies, and that the number of electoral regions is five.
Following thefifth periodic review of Westminster constituencies, new borders for the constituencies and electoral regions were defined by the Parliamentary Constituencies and Assembly Electoral Regions (Wales) Order 2006.[4]
The order detailed the abolition of three constituencies (Caernarfon,Conwy, andMeironnydd Nant Conwy), with three new constituencies to replace them (Aberconwy,Arfon, andDwyfor Meirionnydd). Nine constituencies were subject to "substantial" border adjustments involving the transfer of more than 3,000 inhabitants between constituencies. A further eight constituencies were subject to boundary changes resulting in the redistribution of fewer than 3,000 inhabitants between each constituency, and a further four constituencies were subject to minor boundary adjustments that led to minimal transfers of inhabitants between constituencies. The remaining sixteen constituencies were not subject to any boundary or name modifications.
The three new constituencies straddled the border of the electoral regions ofMid and West Wales andNorth Wales, leading to adjustments in the boundaries of both electoral regions, in addition to minor adjustments to theconstituency of Montgomeryshire also leading to minor regional boundary adjustments. Insouth Wales, the boundaries of the electoral regions,South Wales West, andSouth Wales Central were altered to accommodate changes to the boundaries ofBridgend, andVale of Glamorgan constituencies.
The changes in the boundaries for constituencies and electoral regions of the Senedd came into force for the2007 National Assembly for Wales election.
Section 13(1) of theParliamentary Voting System and Constituencies Act 2011 states that:[8]
The Assembly constituencies are the constituencies specified in the Parliamentary
Constituencies and Assembly Electoral Regions (Wales) Order 2006 (S.I. 2006/1041)24 asamended by—the Parliamentary Constituencies and Assembly Electoral Regions (Wales) (Amendment)
Order 2008 (S.I. 2008/1791)
This details that any further changes to the UK Parliament constituencies in Wales specified in the act (notably the proposed reduction in constituencies to 30) will not be applied to Assembly (Senedd) constituencies.
In a session of the House of Commons where the thensecretary of state for Wales,Cheryl Gillian was questioned on the Labour party's opposition to the decoupling of the two constituencies, she replied:[9]
That is a very interesting thought. Hon.Members are well aware that the Parliamentary Voting System and Constituencies Act 2011 broke the link between Assembly constituencies and parliamentary constituencies. I have agreed that we need to look carefully at the implications of having constituency boundaries relating to different areas and regions for UK and Assembly elections in Wales.
Boundaries of Senedd constituencies and electoral regions were initially not overseen by any statutory review body,[10] following the delinking of Senedd and UK Parliament constituencies in 2011. With the responsibility for proposing alterations to the boundaries ofUK Parliament constituencies in Wales, and reporting to theUK Government, lay with theBoundary Commission for Wales. At the time, both constituencies had the same boundaries. Organisations such as theElectoral Reform Society Cymru indicated a preference for coterminosity (mirroring Senedd and UK Parliament constituencies, especially during the2016 proposed reforms).[11] However, such coterminosity was merely desired and was not enforced by law, meaning any changes to UK Parliament constituencies in Wales did not need to be mirrored for Senedd constituencies. The2023 review of Westminster constituencies reduced the number of UK Parliament constituencies in Wales from 40 to 32, and were used from the2024 UK election.[12] While the Senedd is to introduce larger constituencies composed of pairings of the 32 from 2026.
On 6 May 2020, theSenedd and Elections (Wales) Act 2020 came into force, renaming the Assembly constituencies and Assembly electoral regions of theNational Assembly for Wales, to the Senedd constituencies and Senedd electoral regions of "Senedd Cymru" or "theWelsh Parliament", known in bothWelsh andEnglish as theSenedd.
TheSenedd Cymru (Members and Elections) Act 2024, passed by the Senedd in May 2024,[13] gave the responsibility for conducting boundary reviews of Senedd constituencies to theDemocracy and Boundary Commission Cymru. The commission would be responsible to conduct reviews for specifically both the2026 Senedd election and the 2030 Senedd election, as well as regular reviews thereafter.[14] The2026 review was time-constricted,[15] therefore the 2030 review, the first full boundary review in 18 years, would provide the commission with more flexibility.[16][17]
The Senedd Cymru (Members and Elections) Act 2024 legislated that the2026 election should use 16 six-member constituencies, replacing the existing 40 constituencies and five regions, with the Democracy and Boundary Commission Cymru conducting the review.[18] The law set out that they must be contiguous pairings of the32 UK Parliament constituencies used in Wales since2024,[19] and to only use a single name in both Welsh and English, unless it could be considered unacceptable for a single name.[20] The review commenced in July 2024, withinitial proposals revealed in September 2024,[19][20] andrevised proposals in December 2024. A major change in the revised proposals was the use of mostly Welsh-language names only to meet the condition in law, therefore all (except four) had only one name, its Welsh name.[21] The decision received support fromCymdeithas yr Iaith, but opposition fromAndrew RT Davies, former leader of theWelsh Conservatives.[21][22] In March 2025, the commission published itsfinal determinations,[23] for the 16 constituencies (see§ Proposed constituencies (2026)). The original initial proposal boundaries were re-adopted, while all constituencies were made to useWelsh-only names, with a reiteration of both support and opposition from Cymdeithas and Davies respectively, as well as consultation respondents.[16] By law, the Senedd must put these final determinations into effect for the 2026 Senedd election without alteration.[15]
The following is a list of the proposed constituencies set to be used for the2026 Senedd election. For the current set, see§ Constituencies below.
Senedd constituencies are grouped into electoral regions consisting of between seven and nine constituencies. Anadditional member system is used to elect four additional Members of the Senedd from each region, in addition to the MSs elected by the constituencies. The Electoral Regions boundaries were based upon the pre-1999European Parliament constituencies. At eachgeneral election of the Senedd, each elector has two votes, one constituency vote and one regional party-list vote. Each constituency elects one Member by thefirst past the post (single-member district plurality, SMDP) system, and the additional Senedd seats are filled from regionalclosed party lists, under theD'Hondt method, with constituency results being taken into account, to produce a degree ofproportional representation for each region. Altogether, the sixty Members of the Senedd are elected from the forty constituencies and five electoral regions, creating a Senedd of forty constituency MSs and twenty additional MSs. Everyconstituent is represented by one constituency member and four regional members.
Wales is currently made up of 40 constituencies forelections to the Senedd; the constituencies were the same until the2024 United Kingdom general election but were not linked to those used forelections to the House of Commons of the United Kingdom, with each constituency containing a population of around 60,000.
The borders of each constituency are drawn using Local government boundaries, defined in Parliamentary Voting System and Constituencies Act 2011 as "the boundaries of counties, county boroughs, electoral divisions, communities and community wards".[5][24]
Wales is organised into five electoral regions for elections to the Senedd. Each region contains between 7 and 9 constituencies within them. Each region elects four additional members of the Senedd and roughly contains 500,000 people.
Between the first election in1999 for the thenNational Assembly for Wales, to the2007 election, there were three former constituencies. These constituencies were replaced at the 2007 election, with new boundaries and names.
Three constituency names,Conwy,Caernarfon, andMeirionydd Nant Conwy, became historic, and the new boundaries defined three constituencies with new names:Arfon,Dwyfor Meirionnydd, andAberconwy. Generally, the new boundaries define each constituency taking into account local government ward boundaries, and define constituencies close to equal in terms of the sizes of their electorates.
| Former constituency | Region of former constituency | Replacement constituencies | Regions of replacement constituencies | Preserved county |
|---|---|---|---|---|
| Caernarfon | North Wales | Arfon | North Wales | Gwynedd |
| Dwyfor Meirionnydd | Mid and West Wales | |||
| Conwy | North Wales | Arfon | North Wales | Clwyd |
| Aberconwy | Gwynedd | |||
| Meirionnydd Nant Conwy | Mid and West Wales | Aberconwy | North Wales | Clwyd |
| Dwyfor Meirionnydd | Mid and West Wales | Gwynedd |
| Electoral region (Welsh name) | Number of constituencies | Constituencies (ordered alphabetically) | Electoral population (March 2020)[3] | Image (numbered alphabetically) |
|---|---|---|---|---|
| Mid and West Wales Canolbarth a Gorllewin Cymru | 8 | Brecon and Radnorshire,Carmarthen East and Dinefwr,Carmarthen West and South Pembrokeshire,Ceredigion,Dwyfor Meirionnydd,Llanelli,Montgomeryshire,Preseli Pembrokeshire | 446,524 |  |
| North Wales Gogledd Cymru | 9 | Aberconwy,Alyn and Deeside,Arfon,Clwyd South,Clwyd West,Delyn,Vale of Clwyd,Wrexham,Ynys Môn | 483,739 |  |
| South Wales Central Canol De Cymru | 8 | Cardiff Central,Cardiff North,Cardiff South and Penarth,Cardiff West,Cynon Valley,Pontypridd,Rhondda,Vale of Glamorgan | 523,096 |  |
| South Wales East Dwyrain De Cymru | 8 | Blaenau Gwent,Caerphilly,Islwyn,Merthyr Tydfil and Rhymney,Monmouth,Newport East,Newport West,Torfaen | 491,142 |  |
| South Wales West Gorllewin De Cymru | 7 | Aberavon,Bridgend,Gower,Neath,Ogmore,Swansea East,Swansea West | 413,569 |  |
