Plaid Cymru’s manifesto for the 2026 election makes the case to reform the Senedd’s recently changed electoral system.
During the last Senedd session Welsh Labour and Plaid Cymru came together to reform Wales’ Additional Member System (AMS). AMS has ensured an element of proportionality in elections since 1999 but the dominance of constituency (much more so than in Scotland) has delivered only somewhat proportional elections.
The 2026 election is being held under a closed list proportional system with 16 multi-member constituencies, each electing 6 MSs.
Abolishing the First Past the Post element by replacing AMS was a welcome step forward, but closed list voting puts an incredible amount of power in the hands of parties. Moving towards the Single Transferable Vote or and open list system would address these concerns.
What does Plaid Cymru’s manifesto say on electoral reform?
Plaid Cymru’s manifesto notes that closed lists were not their preferred option for change.
They also call for a system that delivers real choice, ultimately backing STV for the Senedd and Welsh local government.
This is a positive step to improve proportionality, representation and voter choice at elections. However, if they do succeed in changing the system so soon they do run the risk of frustrating voters by changing things yet again. Their call to build consensus in the issue therefore matters considerably.
Recent polls in Wales suggest Plaid Cymru could become the largest party in the Senedd, a significant change from Labour’s dominance since 1999 and at UK General Elections for a century.
Reform are biting at their heels for first place while the Greens hope to win their first MSs.
Meanwhile, polls suggest the Labour and Conservative votes are collapsing.
While the Lib Dems are hoping to keep their sole seat and gain another if possible.
Voters in Scotland are going to the polls on Thursday 7 May 2026 to elect 129 MSPs.
Here’s how the Scotland’s Additional Member System works.
First Past the Post seats
Scotland is divided into 73 constituencies elected via First Past the Post. In this system, you get one vote for candidates in your constituency. The candidate with the most votes in each constituency wins the seat to become the constituency MSP.
On these seats alone, the share of votes cast for each party across Scotland are unlikely to match up with the proportion of seats won. To address this disproportionality, that’s where the other 56 seats come into play.
The country is also divided into eight regions each electing eight MSPs.
With this, you also get another ballot where you vote for a party of your choice. This party list element adds an element of proportionality to the Scottish Parliament so seats broadly match votes (although it’s worth highlighting that the system has proportionality problems that risk being on full display this May).
The allocation of party list seats is determined by list votes cast per party while also taking into account of constituency seats won by each party so seats roughly match votes over all.
If a party does wins lots of constituency seats in a region, they are unlikely to pick up many list seats. This has been the case for the SNP and Scottish Lib Dems in recent years. Similarly, if a party does well on the list ballot but not in constituencies, such as the Scottish Greens, then they will pick up list seats.
The final poll to be published this March suggests the SNP are on track to coming close to winning a majority of seats — on a vote share that doesn’t reflect their projected seat share at all.
The new Survation poll (data collected 16 – 23 March) gives the SNP 35% (constituency) and 32% (list) of the vote. Projections, including from Ballot Box Scotland, suggest this would give the SNP 62 seats. That’s three seats short of a majority and 48% of seats.
That mismatch of seats and votes is shocking, and doesn’t reflect the founding principle of proportionality underpinning the establishment of the Scottish Parliament.
The next Scottish Parliament must address this broken link between seats and votes.
This divergence of seats and votes is driven by the imbalance of constituency and list seats in the Scottish Parliament. 73 out of the 129 seats are elected via First Past the Post, meaning that a party can do well winning lots of these even if their vote share doesn’t reflect their success in winning seats. This is compounded by the limited number of list seats available, meaning other parties can’t be compensated for the SNP winning more seats via constituencies than they would be entitled to if all seats were allocated proportionality.
With the election campaign now underway, there’s a very real chance the polls could change. But as things stand, Holyrood is on track for the most unrepresentative Parliament in its history.
The next Scottish Parliament must review its voting system and commit to reform in order to improve proportionality and voter power over candidates. This poll highlights another reason to address the Additional Member System’s flaws and upgrade Scottish democracy.
The Scottish Parliament’s Additional Member System is significantly more representative than Westminster’s First Past the Post electoral system. But AMS has significant flaws that need to be addressed.
Recent polls suggest that the SNP could win close to a majority of seats – or possibly a majority – on far less than a majority of votes.
This is largely down to the imbalance of constituency seats to list seats alongside one party, in this case the SNP, doing significantly better than other parties across Scottish constituencies.
Since the advent of devolution in 1999, there have been 73 constituency seats to 56 list seats. This means that one party could theoretically win a majority of seats on constituency seats only.
Such an outcome is possible in 7 May 2026, according to recent polling.
Modifying the Additional Member System
One way to address this would be to reform AMS (although it’s worth noting the system has wider flaws that would still persist).
This could involve the introduction of levelling seats if seats don’t match votes. Or else adding two MSPs to each region, creating a more 50-50 sit of constituency and list MSPs.
Alternatively, the number of constituency seats could be cut and replaced by list MSPs. This is an option if decision-makers are wedded to 129 MSPs.
Alternatively, it is worth considering other voting systems. Introducing the Single Transferable Vote, if designed well, could improve proportionality while also empowering voters and giving them the option to vote across different parties.
A more radical alternative would be to introduce an Open List system Proportional Representation with levelling seats to maximise proportionality.
The seventh Scottish Parliament must fix the voting system
So far, Holyrood election results have been broadly proportional. But the 2026 election risks exposes a major problem with the Additional Member System, namely the First Past the Post element.
Concern is growing ahead of the 2026 election that the result after 7 May will be the most unrepresentative Scottish Parliament vote ever.
Proportionality was one of the founding principles of the design of Scotland’s Additional Member System. It’s not perfect, but since 1999 seats have broadly matched votes. Now, due to a combination of the imbalance of constituency to list seats (73 to 56) and one party expected to do well in constituencies despite falling well short of a majority of the constituency vote, the next Scottish Parliament is likely to fall well short of the proportional standards expected.
Are MSPs able to abolish the Additional Member System?
If election projections come true, the next parliament must seize the moment and find consensus to fix Holyrood’s creaking voting system.
The way to do this is through a Bill passed with a supermajority in Holyrood. That’s two-thirds of MSPs. Therefore any change requires broad consensus from multiple parties to meet the magic number of 86 MSPs.
The possibility of electoral reform in Scotland depends on what happens after the election. The bigger the disproportionality, the more pressure there will be on MSPs and ministers to act.
The SNP, Lib Dems and Scottish Greens all support Proportional Representation. And together, they are likely to have a two-thirds majority, but finding agreement on the type of reform will be the challenge – not to mention conflicts in the SNP about maintaining the status-quo for their own advantage versus their commendable party stance on the issue.
There are certainly issues needing ironed out. But there is precedent for this in the devolution era. In Wales, Labour and Plaid Cymru came together to abolish the Additional Member System ahead of their own 2026 vote, and in Scotland, the Lib Dems convinced their coalition partners Labour to introduce STV for Scottish local government.
Holyrood is turning 30 in the next parliament. It’s time to review Scotland’s democratic foundations and reform the voting system once and for all.
A new poll suggests that the Scottish Parliament is on track for a highly unrepresentative election despite Holyrood’s supposedly proportional voting system.
The Ipsos Scotland Political Pulse poll for STV puts the SNP first in terms of list votes, constituency votes and projected seats.
Party
Constituency %
List vote %
SNP
36%
26%
Labour
20%
19%
Green
7%
16%
Reform UK
19%
14%
Conservatives
9%
11%
Lib Dems
10%
10%
In a properly proportional system, seats should broadly match votes cast. But seat projections for this poll indicate a staggering mismatch between seats and votes.
Party
Seat count
Seat %
SNP
60
46.5%
Labour
20
15.5%
Green
16
12.4%
Reform
13
10.1%
Conservatives
10
7.8%
Lib Dems
10
7.8%
The biggest divergence between seats and votes here is with the SNP. Support for the party has fallen dramatically to 26% of list votes and 36% of seats. But projections indicate they are on track for 60 seats – almost half of those available.
The main driver behind this mismatch is driven by the dominance of First Past the Post seats used in Scotland’s Additional Member System, an imbalanced ratio of 73 to 56. This makes it theoretically possible for a party to win a majority on constituency seats alone.
The SNP is doing better than other competitive parties on the constituency ballot, and due to their success, they are on track to win the vast majority of constituency seats and close to a majority of seats overall.
The SNP is set to win more seats than they are entitled to if Holyrood had a mechanism to address parties winning more seats than they proportionally should on the constituency vote. In fact, Ballot Box Scotland estimates that the poll puts them on a staggering 22 seats more than what they should win if seats were determined by the proportional ballot alone in different Scottish regions.
Before the return of Donald Trump, Canada’s Conservative looked set to sail to power in 2025, ending a decade of Liberal rule. But a maverick president and his trade war have shifted the dial dramatically, resulting in Liberal Mark Carney returning as Prime Minister, having called an early election just weeks into the job. The Conservative leader even lost his seat.
There are of course significant geopolitical implications flowing from this development as the world grapple with an emboldened President Trump, but it’s important to examine Canada’s election through the lens of electoral reform.
The flaws of First Past the Post exposed once again
Like the UK, Canada uses the unrepresentative First Past the Post system to elect MPs. As in 2024’s UK General Election, Canada has been given a parliament that doesn’t fairly reflect how people vote.
The Liberals have likely won just shy of a majority of seats on around 43% of the vote (although with some places still counting a majority government is still technically possible). Their vote share is the party’s largest in decades but that doesn’t legitimise the country’s unfair voting system and shouldn’t lead them to winning almost half the seats available.
The Conservatives have in fact won a vote share roughly proportional to the number of seats they won, but that is a rarity in FPTP politics and doesn’t mitigate the fact that millions of Canadians voted Conservative but are without direct Conservative representation.
Then there’s the NDP. The party have suffered at the hands of their former voters turning on them and backing Carney to oppose Poilievre and Trump. The party has been reduced to just 2% of seats on 6% of the vote, significantly fewer than if seats matched votes.
Of course, while the NDP stand across Canada and Bloc Québécois in only one province, the parties won similar vote shares but notably different numbers of seats (the Bloc doing better by winning over 20 seats).
Carney’s win follows two elections (2019 and 2021) where the Liberals under Justin Trudeau won the most seats, forming minority governments, but on fewer votes than the Conservatives.
While Canadians have avoided a third wrong-winner election in a row, seats overall still don’t match votes and voters are stuck with single-member ridings where MPs can’t fairly represent all their constituents.
Canada’s missed opportunity for Proportional Representation
Most campaigners for electoral reform across the English speaking world will know that Trudeau famously promised to abolish First Past the Post ahead of the 2015.
His party leapfrogged from third to first-place, forming a government with a majority of seats, then U-turned, making no effort to reform the voting system despite a decade in power.
Frustratingly, as in the UK, First Past the Post remains in place to this day. Voting reform didn’t even get a mention in Carney’s 2025 manifesto.
Canada, like the UK, has a strong case to give FPTP the boot and embrace Proportional Representation.
The Scottish Conservatives are using the Alternative Vote to elect their new leader, following the departure of Douglas Ross from the top job. The Alternative Vote is a preferential system for single-seat positions, allowing voters to rank candidates in order of preference to ensure the winner receives a broad base of support.
There’s no denying this system is fairer and more representative than First Past the Post. Indeed with at least six candidates standing to replace Douglas Ross, under FPTP the winner could in theory have been elected with less than 17% of the total vote. However, AV negates this possibility.
The Scottish Conservatives ultimately recognise the absurdity of FPTP hence their use of AV to elect their leaders. Furthermore, the party benefits significantly from the broadly proportional Additional Member System used to elect MSPs. If the Scottish Parliament used, First Past the, the SNP would likely have completely dominated at the 2021 election.
Yet the Conservatives continue to back First Past the Post for Westminster elections. If preferential voting is good enough for internal elections, it begs the question why not support the Single Transferable Vote for Westminster votes?
Of course, the way we elect representatives isn’t going to take centre stage in this election. But it’s worth flagging the mismatch between Conservative support for First Past the Post at Westminster with their rejection of it to elect their own leaders.
Conservatives should consider that when ranking candidates one to six in the coming weeks rather than marking an “x” in the box.
A system of Proportional Representation (PR) is one that ensures that how people vote at the ballot box is reflected in parliament. Unlike Westminster elections, in which the unrepresentative First Past the Post is used system to elect MPs (PR), the Scottish Parliament, Welsh Senedd and Northern Irish Assembly all use a form of PR to elect their legislators.
However, just because a legislature uses a PR system, doesn’t mean that results are purely proportional. The extent of proportionality depends on the type of system used and various parameters such as district magnitude and the ratio of list seats to single-member electorates if applicable. When it comes to PR elections within the UK, proportionality is a question of extent for these reasons.
Scottish Parliament
The Scottish Parliament uses the Additional Member System (AMS) to elect MSPs. Voters get two votes: one for their local constituency representative (using a First Past the Post voting system) and one for the regional list. Constituency votes are counted and seats allocated first. Party votes in each region are then added together to allocate regional MSPs. Crucially, regional MSPs are allocated by taking into account the number of MSPs won by each party in the constituencies to ensure broadly proportional results overall.
So, how proportional are Scottish Parliament elections?
One of the best ways to answer this question is to look at the Gallagher Index for Scottish Parliament elections. Simply put, a Gallagher Index for any election is a measure of proportionality that can be used to compare elections across time and between countries. The lower the score for an election, the more proportional it is.
For context, the Gallagher Index for the 2019 UK General Election was 11.8. Canada also uses First Past the Post and had a score of 13.39 in 2019. These are fairly disproportional results.
In contrast, the Scottish Parliament’s scores are on average considerably lower – meaning more proportional as we would expect with its Additional Member System. On average, Scottish Parliament elections have a Gallagher Index of 7. The vote in 2016 was 5.60 and 2021 was 7.03.
Overall, Scottish Parliament elections are pretty proportional but the extend of proportionality is limited by the ratio of constituency to list seats and overhangs. While Holyrood is more representative than Westminster, after almost 25 years of devolution, the Scottish Parliament needs reform.
The Welsh Parliament also uses the Additional Member System to elect its representatives, however, it’s proportionality is even more limited than Holyrood’s. This is mainly due to the fact that the ratio of constituency to list seats is skewed in favour of the former, with just 20 list seats to 40 list seats. Compare that to the 73 list seats and 56 constituency seats in the Scottish Parliament. Furthermore, Welsh electoral regions each only have four representatives compared to the seven in each Scottish region. With fewer MSs per region, the effective threshold for a party getting representatives is significantly higher than in Scotland.
When it comes to the Gallagher Index, since the institution’s creation in 1999, the six elections have had an average score of 10.57. The most recent Welsh election had a score of 9.36. In that election, Labour won more than half of the single-member constituencies but the additional element of proportionality ensure a more proportional result. However, if you dig a little deeper you will see that votes don’t match seats too well – Labour won 29 of the 60 seats available on just 31.5% of the regional vote.
Overall, Welsh elections are more representative than those for Westminster but not as representative as those for Holyrood.
Unlike the Scottish Parliament and Welsh Senedd, Northern Irish elections use the Single Transferable Vote to elect MLAs.
Under STV, the province is divided into multi-member constituencies (with five-members each). Voters rank candidates in order of preference resulting in proportional outcomes overall. Since 1998, there have been seven Northern Ireland Assembly elections with an average Gallagher Index of 4.33. However, the most recent election had a score of 7.80, a high in the modern era under STV.
Overall, Northern Irish elections are very proportional, and as they use STV they don’t have the problems associated with the Additional Member System.
Another set of local elections in England has left a bad taste in the mouths of better democracy campaigners. Yet this time is slightly different. This time – instead of the same old story of unrepresentative councils across the country – we have taken a significant step backwards when it comes to local democracy.
We can debate the merits of directly elected executive mayors another time but if we are to have them – which England does – they should have broad mandates. Until the Elections Act (2022), these mayors were elected via the Supplementary Vote (SV) system.
The SV system isn’t perfect but it gave mayors broad mandates, a crucial check on directly elected executive positions. Instead of making positive reforms, the Conservatives’ regressive Elections Act scrapped this system and imposed First Past the Post on mayoralties across England.
The situation will be far worse in 2024 when metro mayors and Police and Crime Commissioner elections are scheduled. Crucially, 2024 will see the first London mayoral election held under First Past the Post.
Again, the Supplementary Vote wasn’t perfect but it allowed for successful candidates to secure their mandates with broad support. Instead of imposing First Past the Post on mayoralties, the government should have improved the system by implementing the Alternative Vote for mayoral positions. AV would allow voters to rank candidates in order of preference and give directly elected executive mayors broad mandates.
Instead, this development comes on top of the usual story of unrepresentative councils thanks to First Past the Post. Right across England councils were elected with seat shares not reflective of vote shares. English local democracy should be upgrade more widely via the introducing of the Single Transferable Vote (STV) for council elections.
The Lib-Lab coalition of 2003 – 2007 did this in north of the border. Scottish local democracy’s success story since 2007 is undeniable. The country no longer has “one-party state” councils and has a vibrant multi-party democracy at the local level where how people vote at the ballot box is reflected in local councils.
Northern Irish local elections take place in two weeks time using STV. These elections will be a welcome contrast to those we saw in England at the start of the month.
A Conservative government at Westminster isn’t going to upgrade English local democracy any time soon. But the next Westminster power arrangement – possibly some combination of Labour and Liberal Democrat MPs – should look to the Scottish and Northern Irish success stories and upgrade England’s local politics. Preferential voting for both mayors and councillors would be a major leap forward. This year’s elections once again show that change is needed.
Upgrade Holyrood 