There is a new way of voting at the Senedd election this May. How does it work?

Whatever happens in May, the next Senedd election is set to be historic. For instance, recent polling has pointed to the chance that Labour might not be the largest party in the Senedd for the first time. But it’s not just who is sitting in the Siambr that could change. But it’s not just who is sitting in the Siambr that could change.

The way we vote for our Members of the Senedd (MSs) is also set to change with the new ‘closed proportional list’ system. Yet, many voters are still not fully aware of how the new system works.

How have Senedd elections worked so far?

Since its creation, the Senedd has used a mixed system called the Additional Member System. 40 Members were elected using Westminster-style First Past the Post while the remaining 20 were elected through a proportional system designed to balance things out.

Without enough members to properly scrutinise the legislation passing through the Senedd, it always suffered from a lack of capacity – especially compared to the Scottish Parliament on 129 seats and the Northern Ireland Assembly on 90 seats. When MSs voted to increase the size of the Senedd to 96 to better match their workload, the inevitable question of how these new members should be elected came up. MSs decided to adopt a ‘closed proportional list’ system.

How the new system works

Wales will be divided into 16 new constituencies, each one electing six Members of the Senedd. Instead of having two votes, you will now have just one. You can vote for a party or an independent candidate. Seats are then shared out based on how many votes each party receives.

Let’s break down how a ‘closed proportional list’ works in practice.

What does the proportional part mean?

Under the new approach, seats are allocated in proportion to the vote in each constituency. If a party wins half of the vote, it is likely to win three out of six seats.

The system uses a method called D’Hondt, after its inventor, to decide who gets each seat.

Counting takes place in rounds, with the party with the highest total in each round getting an MS. After each round they divide the number of votes cast for each party by the number of seats they have already won, plus one, and the party that now has the most votes gets the next MS. This process continues until all 6 seats are filled.

What is the list?

Parties have lists of candidates for each constituency. These are published in advance and printed on the ballot paper. If a party wins one seat, it’s the candidate at the top of the list is elected. If they win three, the top three on that party’s list become MSs.

Independent candidates can stand too. And if they receive enough support, they can win a seat in the same way.

What does it mean to be a closed list?

The final part of the closed proportional list is the fact that voters don’t get a say on who the top candidate is for each party – the order of the list has been ‘closed’ and can’t be changed. This is actually pretty rare in countries with similar systems, and those that use ‘closed’ lists like Portugal have democracy campaigners fighting against them.

One alternative is an ‘Open’ list, where voters can vote for their favourite candidate, and the list is ordered based on this. The most popular candidate from each party takes the top spot when it comes to distributing seats. Another option is the Single Transferable Vote, where voters rank the candidates.

What does this all mean for me?

In Westminster you have a single local MP representing you, and quite often this will be someone you didn’t vote for and doesn’t represent your outlook or values. In the new Senedd, because all seats are allocated based on vote share with the new system, you are far more likely to have a representative – in this case, an MS from the party you voted for – that will fight your corner.

But what if you don’t like the candidate a party has put at the top of their list? Ourselves, the Committee on Senedd Electoral Reform and the Expert Panel on Assembly Electoral Reform all recommended the Single Transferable Vote (STV) as it would have given voters more influence, but MSs decided against it. After the next Senedd election in May 2026 Members of the Senedd will have the chance to review the closed list system, and we’ll be arguing that ‘closed’ lists aren’t good enough for Welsh voters to hold MSs to account.

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