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Proposals to Reform the Senedd Explained

Following the announcement today on Senedd reform, Cathy Owens and Fergus Turtle have outlined the changes we may see in how it would be elected.

Senedd Reform: what does it mean?

The much-anticipated proposals to reform the Senedd have finally emerged with the First Minister and the Leader of Plaid Cymru setting out their agreed vision this morning.

The proposals are part of the Co-operation Agreement between Labour and Plaid Cymru, and the plans would likely be agreed by the Senedd, where a two-thirds majority is required, against opposition from the Conservatives. Both Labour and Plaid Cymru are likely also to require internal votes on the proposals. 

So, what do they say and what does this actually mean for the Welsh Parliament and our future elections?

Number of Members

The first headline is that the next Senedd will be bigger, growing from 60 to 96 members. This idea of enlargement has been commonly aired since the beginning of devolution in 1999. In fact, the Siambr is designed so that more seats can be added. These calls have grown as the Senedd’s powers have increased.

Specifically, the Expert Panel on Assembly Electoral Reform recommended in 2017 that the Senedd be given more members to deal with the large workload, deeming 80-90 members to be an appropriate size. The Senedd Committee on electoral reform also endorsed 80-90 members in 2020.

Clearly then 96 a significant increase compared to what we might have been expecting. It will certainly make a significant difference to the operation of the Senedd.

Electoral System

With a change in the size of the Senedd it was likely that there would have to be some changes to the electoral system. Both the Expert Panel and electoral reform Committee recommended STV, a proportional system with multimember constituencies and ranked choice voting. You may have seen this in action in Northern Ireland, or elections in the Republic of Ireland.

This would have made the Senedd considerably more proportional and providing more opportunities for smaller parties. It also makes the outcome more difficult to predict.

The ranked element means voters rank their preferred parties or candidates in order, and voters second and third preferences can impact on the outcome. Because of the ranking system and the transferred preferences, it tends to penalise parties who are disliked the most.

The Labour and Plaid Cymru leadership have instead decided on on the d’Hondt system based on sixteen 6 member constituencies. This is also a system of proportional representation but favours larger parties over smaller ones. It is already being used to calculate regional lists at Senedd Elections as well as UK elections to the European Parliament.

Specifically, the system awards a seat to the list (a slate of candidates proposed by a party) with the highest quotient. A party’s quotient is their number of votes divided by the seats they have already won in that constituency, plus 1. This is then repeated until all seats in the constituency have been allocated.

The regional list elected in this way at the Senedd effectively rewards parties that come second and third in lots of places. The pattern we have seen since 1999 is that Labour tend to come first in many constituencies, which mean they don’t win very many regional seats. The regional seats are then divvied out to parties who do well across the region but don’t win constituencies.

This list system gives a bit more control to parties, who present a list with a predertmined order. Some would argue it reduces the options available to votes to express a preference over individuals. 

Since the Senedd was established, it also allowed smaller parties to gain seats, with the threshold in some regions reaching only 6%. So a party would only need to win around 6% across a region to win a seat. But again the maths can vary, and the threshold was different in each region at the last election, ranging from 6% to 9%.

Under this system, parties such as the Greens and the Abolish the Assembly party have not reached that threshold, but it is a system that has served the Liberal Democrats well over the years, and helped UKIP secure seats in 2016.

Without the split between constituencies and regions, the d’Hondt system will count across the 6 seats in twinned constituencies. It is likely, therefore, that the parties outside the big three will need to achieve a relatively high amount of the vote in constituencies to gain seats. This is a high bar for parties like the Greens and even the Liberal Democrats whose votes are usually thinly spread.


With boundary changes and a reduction of Welsh seats at Westminster another issue has been what the electoral boundaries for the Senedd would be going forward. How would they account for enlargement and a different electoral system, and would they continue to mirror Westminster districts?

There are currently 40 constituencies at the Senedd, which are exactly the same as those at Westminster. The coterminous boundaries, as they are described, are seen as valuable, as it makes it clearer to the electorate. Have different MPs and MSs and then living in different non-devolved and devolved constituencies could be described as confusing, up to a point. Local authority boundaries are not quite the same.

The Senedd could have decided to stick to the same 40 constituencies, and twinned those to give 80 seats. We understand that there was a view that if Senedd reform was to happen, with a consequential political price, it might as well be meaningful, and reach nearer 90 or 100. Given the row to come, why go through it for 20 extra seats?

The proposal, therefore, is that constituencies will continue to be tied to their Westminster counterparts but will be combined in pairs to account the other changes. As the UK Government intends to reduce the number of Westminster parliamentary constituencies in Wales from 40 to 32 following a boundary review. The maths makes it easier to reach 96 using the d’Hondt system – with 3 members per constituency but elected in groups of six in twinned constituencies.

One fly in the ointment is that the changes have yet to happen at Westminster, and the last time it was attempted, the proposal ran out of road. We’ll assume for now that these changes will take place, the announcement effectively says ‘we need to agree to the 96 with d’Hondt on twinned constituencies as an interim, otherwise we won’t have time to change things before the next election’.

The agreement reached at the Senedd also says there will be a boundary review of Senedd constituencies to take effect in the next Senedd term. This gives the Senedd some flexibility to respond to whatever is finally agreed at Westminster.

Exactly which constituencies are paired in the meantime will be up to the Boundary Commission.


The proposal finally suggests enshrining gender quotas in law and mandatory zipping. Exactly what the details of the quota are we will have to wait and see but parties’ lists will likely have an equal number of women.

This will no doubt increase the number of women elected in those parties who have poor gender representation at the Senedd at present. Labour are already on 50%, but Plaid Cymru are only on 30%, and only 20% of Conservative Senedd Members are women.

Zipping will relate to positions on the lists – with alternately a woman and man on the lists – but with the detail to come about which goes first. Potentially this could be agreed in ‘twinned twinned constituencies’ so that one party’s list in a twinned group of six starts with a woman, and with a man in the twinned group next door.

Examples show that zipping significantly increases the number of women elected, as they are guaranteed either first or second on a list.


For a bird's eye view.
Am olwg oddi uchod.

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