Welsh elections 2026: Senedd Cymru (Welsh parliament)

The Senedd Cymru (Welsh parliament) in Cardiff is the devolved legislature of Wales. It is unicameral, meaning that, unlike the UK parliament at Westminster, it only has one chamber.

Why was the Senedd created?

Senedd Cymru was originally created as the National Assembly for Wales in 1999 as part of the Labour UK government’s plans to devolve power to Scotland, Wales and Northern Ireland. Devolution to Wales was intended to allow for decisions on key services to be taken by “people directly elected by, and accountable to, Welsh voters”, and “above all else… provide a clear and distinctive voice for Wales”. ⁷ https://commonslibrary.parliament.uk/research-briefings/rp97-129/

The creation of the Welsh assembly was approved in a referendum in 1997 (in parallel with a vote in Scotland) with a slim majority of 50.3% of votes cast in its favour, on a turnout of 51.3%. Previous proposals for a Welsh assembly had been defeated in a 1979 referendum, with 79.7% of votes cast against the proposals.

In 2017, the assembly was also given the power to change its own name. In November 2019, this power was exercised, as the assembly voted to change its name to bilingual Senedd Cymru or Welsh Parliament. This came into effect on 6 May 2020. 

What powers does the Senedd have?

The Senedd has power to make laws over many key areas of Welsh life. These include most aspects of health and social care, housing, education, local transport, economic development, social services, language and culture, the environment, and local government.

When initially created, the Senedd was able only to pass secondary legislation in devolved areas. The Government of Wales Act 2006 gave the Senedd limited powers to pass primary legislation. Following a referendum in 2011, the Welsh electorate voted in favour of extending primary law-making powers to all areas where the Senedd has responsibility. Since 2011 it has been able to pass primary legislation in the form of Acts of Senedd Cymru.

Since 2014, it has also held some tax-raising powers, including control of local taxes, taxes on property transactions (stamp duty land tax) and landfill, and the power to vary income tax rates in Wales. 

The Senedd has fewer powers than the Northern Ireland assembly and Scottish parliament. In particular, it has no power over policing and justice, which remain the responsibility of the UK government. 

How is the Welsh government funded?

The majority of the Welsh government’s funding comes from an annual block grant from the UK government calculated using the Barnett formula.

This system increases or decreases the funding provided by the Treasury to the Welsh government based on changes to spending in England on functions that are devolved, taking into account population share.

Wales receives 105% of any spending increases in England, on a per-capita basis. So for example, if spending on health care in England increases by £100m, the Welsh government funding would rise by £5.9m, since Wales’s population is 5.6% of England’s, and this is then multiplied by 105%. However, under the terms of the formula, the Welsh government need does not need also to spend this extra sum on health care.

The Welsh government also receives income from devolved taxes and a share of Welsh income tax revenue. 

Which parties are currently represented in the Senedd?

There are currently 60 MSs, representing five political parties in the Senedd. The largest party is Welsh Labour, which holds 29 seats and has been in government since 1999.

The next largest parties are the Welsh Conservatives and Plaid Cymru, with 14 and 13 members respectively. There is also one Liberal Democrat, one Reform member and two independent members. 

What is the new electoral system for the 2026 Senedd election?

From 1999 until 2021, the Senedd was elected using the Additional Member System, in which voters cast one ballot for an individual constituency candidate and a second for a regional party list. 

Following the passage of the Senedd Cymru (Members and Elections) Act 2024, the 2026 election will be held under a closed list proportional system. Under this system, the number of Members of the Senedd (MSs) will increase from 60 to 96, and the number of constituencies will decrease from 40 to 16, with each new constituency electing six MSs.  ⁸ Welsh Government, Welsh Elections (Coronavirus) Bill, https://senedd.wales/media/kukp15ds/pri-ld14059-em-e.pdf   

Under the new system, votes are cast for a political party rather than an individual, unless there is an independent candidate. Political parties can list up to eight candidates for each constituency and independent candidates can also stand for election. If a seat becomes vacant during a Senedd term, it will be filled by the next candidate on the party list or, if the outgoing MS is independent, it will be left vacant until the next general election. This means that by-elections will not occur under the new system. Seats are allocated based on the share of votes each party or independent candidate gets.  

The D’Hondt formula is used to make sure seats are allocated to closely reflect their share of the vote. For example, if a party wins 50% of the vote in a constituency, they will likely win three of the six seats in that constituency. The top three people on the party’s list for that constituency will then be elected to those seats. Independent candidates can gain election if they win enough votes in a constituency to be allocated a seat. Since there are six seats in each constituency, an independent candidate requires approximately 16% of the vote to win a seat.  

How do Senedd elections work?

Under the closed list proportional system, which candidates are selected depends to a large extent on the order of the party list, which is decided by the party. Voters are unable to express preference about a particular candidate, which reduces voter choice and can be argued to reduce the direct accountability between voters and MSs.  

The closed list system may benefit emergent parties in Wales to the detriment of more established parties, whose candidates are more likely to have a strong personal profile. This may help Reform, who are recognisable at a national level but lack a well-established local party presence or well-known candidates across Wales.  

How will a new government be formed after the 2026 Senedd election?

The Senedd must nominate an MS for appointment as first minister within 28 days of a Senedd election. Any MS is entitled to stand to become first minister. If there are two or more nominations, MSs will vote on who they want to be first minister, who is then be formally appointed by the King.  

For example, following the resignation of Vaughn Gething in July 2024, Eluned Morgan (leader of Welsh Labour), Andrew RT Davies (leader of the Welsh Conservative Party), and Rhun ap Iorwerth (leader of Plaid Cymru) all nominated themselves to be First Minister. MSs then voted for their preferred candidate with Eluned Morgan winning 28 votes compared with 15 for Davies and 12 for ap Iorwerth.  

If no nominations for first minister are made or if the Senedd is unable to select a new first minister within 28 days, then the process to hold an ‘extraordinary general election’ is triggered.

After selection, the first minister will appoint cabinet secretaries and ministers to work in Welsh government departments.  

Which parties could form a government after the May 2026 Senedd election?

Usually, the party that wins the most seats in the Senedd election would be expected to lead the Welsh government. This has been the case throughout the 26 years of devolution.  

Under the new system, it is unlikely that any party will win the 49 seats required for a majority in the 2026 Senedd election. The largest party will likely require the support of other parties to govern – which could come via a formal coalition, a looser support agreement (such as ‘confidence and supply’) or on a more ad hoc basis if a minority administration were formed.  

Based on polling since May 2025, the two largest parties in the Senedd after the 2026 election are likely to be Plaid Cymru and Reform UK. Rhun ap Iorwerth, the leader of Plaid Cymru, has ruled out a coalition with Reform UK and the Conservatives, meaning a coalition on the left of Welsh politics would likely consist of some combination of Plaid Cymru, Labour, the Green party, and the Liberal Democrats. It is not known whether the Conservatives or any other party would be open to supporting a Reform-led government in Cardiff.  

If Reform became the largest party in the Senedd, other parties could opt to allow it to form a minority administration without offering active support. This would leave the new government vulnerable to defeat in the Senedd, including on confidence matters such as the passage of budgets.

It is also possible that two or more smaller parties could form a coalition government that excludes the largest party in the Senedd. Although this has not happened before, there was an attempt in 2007 to form a coalition between Plaid Cymru, the Conservatives and Liberal Democrats, which would have consigned Labour – the largest party – into opposition.

Who are the likely candidates for First Minister?

The current party leaders and likely candidates for the post of first minister are:

• Eluned Morgan, the current first minister and leader of Welsh Labour
• Rhun ap Iorwerth, leader of Plaid Cymru
• Darren Millar, leader of the Welsh Conservatives
• Jane Dodds, leader of the Welsh Liberal Democrats
• Anthony Slaughter, leader of the Welsh Green Party

Reform UK have not yet chosen a leader of the party in Wales. They have one sitting MS – Laura-Anne Jones -– who defected from the Conservatives to Reform in July 2025. 

What has happened at previous Senedd elections?

Welsh Labour has been the largest party in the Senedd since it was created, winning between 26 and 30 seats at every election since 1999. Labour has also been in government, either in coalition or alone, throughout the era of devolution.

At the 2021 election, Labour equalled its best performance, winning 30 seats for the third time. The Conservatives also achieved their best result in terms of both their share of the vote and seats, electing 16 members. Plaid Cymru won 13 seats, making a net gain of one seat on the last election, while the Liberal Democrats retained one seat.  

Since the 2021 Senedd election, there has been one by-election. This was held on 23 October 2025 in Caerphilly. Plaid Cymru won the seat with 47.4% of the vote, Reform UK came second with 36% and Labour third with 11%. Labour had previously held the seat since the Senedd was established in 1999.