Introduction
Darren Hughes, Chief Executive
The General Election in 2024 was not only the most disproportional election in British electoral history but one of the most disproportional seen anywhere in the world. Underneath this headline lies a story – one of a volatile electorate, fragmenting party system and an electoral system that cannot keep up. The result for voters, and for parties, is a system out of step.
This was an election of records broken for all the wrong reasons. Alongside record levels of disproportionality, record lows in trust and engagement delivered a significant drop in turnout. Those who did turn out delivered a message – the party system and certainties of old are changing.
The 2024 General Election was the first in which four parties gained over ten percent of votes and five parties over five percent of votes. Labour and the Conservatives recorded their lowest combined vote share (57.4%) in the era of universal suffrage, with other parties and independents taking over 40 percent of the votes.
This was an election of multi-party voting, breaking away from the Brexit-driven two-party squeeze seen in the previous two elections, but not translating into a multi-party parliament. The votes piled up for the Reform Party and the Green Party, who received over 4 million votes and nearly 2 million votes respectively, but these did not translate to their fair share of seats, Reform gaining five seats, and the Greens only four.
Volatility also reached a new high. Voters continued to shop around, switch parties and decide later who to vote for. The electoral shocks of the last decade continue to influence our politics, forging new political alignments, and uncertainty for parties and voters alike.
Westminster’s voting system is not designed for this electoral landscape and, as a consequence, delivers results that are not only highly disproportional but uncomfortably fragile. Small changes in vote share over the last decade have resulted in vastly different results.
Voters also continued to try to make the electoral system work for them by voting tactically – nearly a third, again at this election, said they would be opting for a party that wasn’t their first choice in order to keep out another.
But it is not just the voters who were remarkable at this election. With turnout down to 59.9%, only narrowly missing the previous low experienced in 2001 (59.4%), non-voters also spoke loudly. At 40.1%, the non-vote was higher than any party’s vote share.
We have delved underneath the headline election outcomes to reveal the full picture from this election and we have analysed what the election might have looked like under a range of different electoral systems. As UK General Elections continue to break records for all the wrong reasons, it is time to consider how things could be better.
Acknowledgements
We would like to thank the whole ERS team for their contributions to producing this report.
Produced with the generous support of
We’d like to thank everyone who donated to support this report, their names are listed at the end of the publication.
Ten Key Numbers from the General Election
In Numbers
For an election where the result felt known weeks if not months, before the exit poll, the 2024 General Election was also one of surprises and uncertainties, reflecting the increased volatility and multi-party nature of electoral contests in the UK.
- 23.7% was the Conservative’s vote share, making it their lowest ever recorded. The previous low was in 1832 (29.2%).
- 72 MPs is a new record for the Lib Dems. Their vote share was 12.2%, 4.3 points higher than the 7.9% of votes they received when they recorded their lowest ever number of MPs at the 2015 General Election (8 MPs).
- 73.7% of votes did not directly affect the outcome in 2024 – 21.2 million votes in total.
- 42.6% of votes went to parties (and independents) other than Labour or the Conservatives, which is a record high.
- 59.9% was the turnout at the 2024 General Election. This is the second lowest voter turnout since universal suffrage was introduced, only narrowly beating the 2001 low of 59.4%.
- 4 parties gained over ten percent of votes (and five parties over five percent of votes) for the first time ever. 1 in 3 voters said they made a tactical vote instead of voting for their preferred party.
- 411 seats: that’s how many Labour won with their landslide victory, on 33.7% of the vote – a lower vote share than their election loss in 2017.
- 344 seats, out of the 650 across the UK, are not Labour/Conservative contests. In these seats other combinations of parties make up the top two contenders.
- 554 constituencies (85% of all seats) elected their representative on less than 50% of the vote.
The 2024 General Election under First Past the Post
The 2024 General Election
Labour’s highly efficient vote spread enabled the party to double their seat share to 411 MPs* – a substantial majority of 63.2% of seats on just over a third of the vote (33.7%).
This was only a 1.6 percentage point increase on their 2019 vote share, yet this small increase gave the party a 32-percentage point increase in seats. In 2015, a 1.5 percentage point increase for Labour saw the party lose 26 seats.
*The Speaker is not included in the total Labour seat or vote share throughout the report. This is because the Speaker does not sit as a party MP, nor vote. It is also traditional for the Speaker to be elected unopposed in their constituency in which they stand as ‘The Speaker seeking re-election’ rather than on a party ticket.
This mirrors the 2019 dynamic in which the Conservatives experienced a similar shift and increased their seats by 48 on only a 1.3% increase in vote share.
In 2024, the results swung the opposite way for the Conservatives who lost around half of their 2019 vote share and 244 seats – two thirds (67%) of their 2019 seat share.
Results under FPTP are increasingly volatile and fragile.
Small changes in vote share led to significant shifts in seat share
Change in party vote share and seat share 2019 and 2024
The Arrow Plot shows seat share and vote share for Labour, Conservatives and Liberal Democrats in 2024 and 2019. In both the 2019 and 2024 elections, small changes in vote share led to significant shifts in seat share.
The Liberal Democrats achieved a more proportional 11.1% seat share for their 12.2% of the vote, but other parties missed out. The Reform Party received over 4 million votes (14.3% of vote share) and only five seats (0.8%), whilst the Green Party got just four seats for close to 2 million votes (0.6% of the seats for 6.7% of the vote).
Because geography plays an outsized role in First Past the Post elections, parties can gain significant national vote shares without that being reflected in the results. We can see the impact of this by looking at how many votes were cast for each party compared to how many MPs were elected for that party. For instance, Reform UK, with 4 million votes and 5 MPs, had 823,522 votes per MP elected. The Green Party, with nearly 2 million votes and 4 MPs, had 485,951 votes for every MP elected. By contrast, Labour had 23,622 votes for every MP elected and Sinn Féin 30,127 votes per MP.
Millions of voters cast votes for candidates that didn’t get elected in their constituency and these votes ended up making no difference to the makeup of Westminster, leaving 57.8% of all voters unrepresented. Parties can build up high levels of support across the country, but still fail to win the representation they deserve in Westminster.
This also meant that the election result ended up being the most disproportional in history.
Disproportionality is measured by a DV (Deviation from Proportionality) score. There are different DV measures. The Loosemore-Hanby (L-H) index looks at the deviation between each party’s vote share and its seat share. If a party obtains 25% of the votes and 20% of the seats, the deviation is 5. The index adds up the absolute values of these deviations across all parties running in the election and divides the total by two. The higher the number the greater disproportionality. On the Loosemore-Hanby measure, the General Election scored 30.1. This beats the previous high score, at the 2015 general election, of 24.
Another measure of disproportionality is the Gallagher index. The Gallagher (least squares) index, produces a figure where zero indicates perfect proportionality and the higher the number the greater the disproportionality. This measure finds that 1983 was the previous most disproportional result with a score of 20.6. The 2024 General Election scored 23.6 on this index.
On both these measures the 2024 General Election was not only the most disproportional in the UK but also one of the most disproportional seen anywhere in the world.
The 2024 General Election was significantly more disproportional than any other recent election
DV scores for UK elections over time
Comparing DV scores for UK General Elections under FPTP to elections held in the UK using proportional electoral systems shows both better proportionality, and less variation, under PR systems compared to FPTP.
A Changing Electoral Landscape
Multi-Party Voting
With votes for parties, and independent candidates, other than Labour and the Conservatives reaching a historic 42.6%, the 2024 General Election saw a significant shift towards multi-party voting.
This election returned the highest number of MPs from third parties (MPs from parties other than Labour and Conservative) since the 1923 general election. 117 third-party MPs were elected, representing 18% of all MPs. The 2024 General Election is the first time since 1923 that the number of third-party MPs elected has been above 100.
The number of Conservative/Labour contests has also declined. In 2024, Labour and the Conservatives were the top two parties in fewer than half of constituencies (306 out of 650 seats). This compares to 432 out of 659 seats at the 1997 general election.
Yet First Past the Post is an electoral system designed for a two-party system. When more parties are in contention, as is the case when voters spread their choices across multiple parties, the winner’s share of the vote is often reduced. As a result, winning candidates get across the line with less than a majority and occasionally, less than a third of constituency support.
85% of all constituencies have an MP who won less than 50% of the vote
Winning vote share by constituency
Chart shows the percentage of the vote won by the winning candidate in each constituency, by party. All the dots to the left of the middle line are constituencies won on less than 50% of the vote.
554 constituencies (85% of all seats) elected their representative on less than 50% of the vote share (this compares to 229 constituencies in 2019) and 266 constituencies (41% of all seats) elected their representative on less than 40%. Many more seats are seeing more than two parties get sizable vote shares, which, under FPTP, reduces the eventual mandate for the winning candidate.
As well as an increase in multi-party voting and decline in Labour/Conservative contests, another indication of this shifting electoral landscape was the change in seats which had been so safe they had been held by the same party for over a century.
Going into the General Election, 111 constituency seats had been held by the same party for over 100 years. The Conservative party held 94 of those seats and Labour 17 seats. Forty-six of these seats changed party hands at the election – all former Conservative seats – and only four of the 48 seats still held by the Conservatives have majorities of over 10,000. Of the 17 seats Labour has held for over a century, only three have majorities over 10,000.
The number of safe seats that switched at this election is largely due to the collapse in the Conservative vote, but this also highlights the extent of voter volatility and partisan dealignment. In 2019 Labour also lost seats that they had held for decades. Voters are switching parties, and shopping around like never before.
The Unheard Millions
Voter Turnout and Unrepresented Votes
Turnout at the 2024 General Election was just 59.9%, narrowly missing the previous historical low turnout of 59.4% in 2001.
At 40.1%, non-voters represented a higher percentage of the electorate than any of the parties’ vote shares. This is the first time this has happened since the low turnout elections in 2001 and 2005.
However, what the turnout figure fails to show is how many people were unable to vote because they weren’t registered to vote in the first place. Estimates suggest that voting registers are only 86% complete meaning, in addition to the 19 million who didn’t turn out, there are millions more people left out of the election altogether. ERS estimates the total number of eligible people missing, or inaccurately registered, to be in the region of 8.2 million across England, Scotland and Wales.
In total 28.8 million people voted in this election (it was 32 million in 2019 and 32.2 million in 2017). With around 27.5 million people not participating either by not turning out or not registering, nearly as many people didn’t vote in this election as did.
Nearly as many people didn’t vote in this election as did
Number of 2024 voters, registered non-voters and unregistered persons
Our estimates show that nearly as many people didn’t vote as did turnout.
For those who turned out in the election, some will have found that their vote had less of an impact on the result than others. Under FPTP, the winning candidate only needs to beat the second placed candidate by a single vote. Any votes the winner received above this make no difference to the result and all votes for unelected candidates are disregarded. This means that in most constituencies, only a small percentage of votes count.
Each constituency vote can be broken down into:
- Decisive Votes — votes cast that a candidate needed to be elected.
- Unrepresented Votes — votes cast for candidates that weren’t elected.
- Surplus Votes — votes cast for a candidate above what was needed for them to be elected.
Millions of voters in the UK made no difference to the result, as their vote went to a candidate who wasn’t elected, or the candidate they voted for already had enough votes to win. Importantly, not all electoral systems treat votes in this way. Some systems take a second or third preference into account if a voter’s first preference isn’t elected, and others ensure that more preferences count in the first place, sharing seats out proportionally over a larger area.
In the 2024 General Election, 57.8 percent of voters (16.6 million) were unrepresented, and 15.9 percent of votes (4.6 million) were surplus. That’s a total of 73.7 percent of votes disregarded in 2024 – 21.2 million votes. The last time we saw a similar percentage of votes ignored in this way was in 2015 – another election characterised by significant multi-party voting.
Under FPTP, a greater number of parties contesting each seat means more votes are likely to be ignored. So whilst there is increasing support for ‘third parties’, this shift is not able to translate into seats under FPTP and fewer voters see their choices reflected in the result.
Some parties will find their votes piling up in safe seats (surplus votes) and some parties will see more of their vote going to candidates who aren’t elected (unrepresented). This is because geography plays an outsized role in determining results under First Past the Post which rewards an efficient geographical vote spread over vote share.
Labour is the only party where a majority of their voters have an MP they voted for
Ignored votes by party
Chart shows the percentage of votes that are decisive, surplus and unrepresented by party
Labour’s staggeringly efficient vote spread can be seen in this graph with only 21.7% of the total Labour vote going to Labour candidates who weren’t elected and nearly 50% of Labour votes being decisive votes for Labour candidates. Conversely, for the Green and Reform parties, over 90% of their votes did not contribute to winning seats.
The SNP saw a large percentage of votes going unrepresented and the Conservatives also saw a significant percentage of their vote share going on candidates who did not get past the line.
Despite a highly efficient vote, Labour did, as with previous elections, stack up a significant number of surplus votes with their vote share being concentrated in key urban areas like London and in parts of the North West such as Liverpool and Manchester. The Liberal Democrats and Plaid Cymru also had notable surplus vote percentages.
The darker areas on each of the maps show a greater number of votes being surplus, decisive, or going unrepresented by area. The darker areas on the surplus map show how votes are stacking up in urban areas with large Labour vote shares, like London and parts of the North West. Whilst the unrepresented votes map shows the extent of unrepresented votes right across the country.
Electoral Volatility and Tactical Voting
Shifting Voter Preferences
Volatility – voters switching between parties – has been a growing feature of UK elections over the last decade.
Volatility can be measured at the aggregate level – how much the national party vote share changes between elections, or at the individual level – the proportion of voters switching party.
The 2024 General Election saw a new record for aggregate volatility, beating the previous 2015 record but remaining lower than 1931, indicating the biggest change in party vote shares for nearly a century. The change between elections was also stark with aggregate volatility at the 2024 General Election more than double the figure in the 2019.
Volatility is partly a result of partisan dealignment with fewer voters holding strong attachments to a single party, but it can also be affected by electoral shocks which change political alignments.
Realignment has also increased the number of ‘cross-pressured’ voters – voters who find themselves aligned with one party on economic issues and with another on social ones. In 2019, cross-pressured voters in ‘red wall’ seats (those who were closer to Labour on economic issues but socially more conservative) played a significant role. In 2024, attention fell to those voters who were traditionally closer to the Conservatives on the economy but more liberal on social issues. These ‘cross-pressured’ voters are more likely to decide later who to vote for and more likely to switch party between elections, contributing to volatility.
In the final week of the 2024 General Election campaign, up to 12% of the electorate were still undecided who to vote for. Typically this figure would fall to under 10% by the final week of the election. Those undecideds were more likely to be women, previous Conservative voters, and to have voted Leave in the EU referendum.
During the General Election campaign we asked voters how easy they were finding it to decide who to vote for. While almost two thirds (63%) of likely voters said they had found it easy to make their decision on who to vote for, as many as one in four (26%) said it had been difficult. Around a third of those intending to vote Conservative (30%), Liberal Democrat (32%) and Green Party (34%) said they had found the decision difficult whilst only one in five Labour voters (18%) said so.
We also asked voters if they had considered voting for another party or candidate. Among those who were intending to vote, almost two in five (38%) said they had considered voting for another party or candidate. This rises to almost three in five (57%) Liberal Democrat voters and half (49%) of Green Party voters.
For many voters, the difficulty in making a decision is not just about trying to find a party that aligns with their preferences but also calculating whether that party has a chance of winning in the constituency they live in.
We polled voters in the second week of the campaign, going into the final week, and after the election about tactical voting. In all three polls we found at least one in four voters planning to cast a tactical vote: voting for a party other than their first choice to keep out another party they liked less. Two weeks into the election campaign we found that 23% of voters were intending to vote tactically, with one week to go this figure was 26%. Those planning to tactically vote rose to at least a third of those aged 18-34 (37%), those intending to vote Liberal Democrat (35%) or Labour (33%).
Our post-poll research showed that 28% of voters had opted for a tactical vote, similar to the 32% who said so in 2019.
Tactical voting has long been a feature of First Past the Post elections. With only one candidate making it across the line, voters are forced to take constituency voting patterns into consideration when making their choice. However, increased multi-party voting and volatility make these judgements more difficult. A range of tactical voting sites have emerged to help guide voters into making an effective tactical vote but of course, not all tactical votes end up working as expected. Ultimately voters should be able to vote for the party who they want to win knowing that their vote won’t be wasted, this is only possible under a system of PR.
The Alternatives
How the results would have looked under PR
There are many electoral systems which fare much better than FPTP in terms of proportionality, voter choice, and representation. In other words, systems that work much better for voters.
We have modelled three forms of proportional representation (PR) that many voters in the UK use, or have used in the past. All three have produced broadly proportional results, that better reflect the choices made by voters across the country. Based on 2024 voting patterns, all three PR projections produce a likely Labour-led, left-wing governing coalition and a more diverse right-wing opposition.
|
FPTP |
STV |
AMS
(50:50) |
AMS
(68:32) |
List PR |
Labour |
411 |
227 |
228 |
282 |
194 |
Conservative |
121 |
148 |
139 |
134 |
147 |
Liberal Democrats |
72 |
71 |
73 |
58 |
78 |
Scottish National Party |
9 |
16 |
16 |
18 |
16 |
Reform UK |
5 |
90 |
100 |
75 |
109 |
Independents |
5 |
5 |
0 |
2 |
0 |
Green Party |
4 |
67 |
71 |
57 |
83 |
Plaid Cymru |
4 |
8 |
4 |
5 |
5 |
Northern Ireland Parties* |
18 |
18 |
18 |
18 |
18 |
The Speaker** |
1 |
0 |
1 |
1 |
0 |
Total |
650 |
650 |
650 |
650 |
650 |
*Results for parties in Northern Ireland were not modelled as part of this exercise.
**Due to the uncontested nature of the Speaker’s election, it has only been modelled for AMS.
Single Transferable Vote
Voters across Scotland and Northern Ireland already use the Single Transferable Vote to elect their local councils, and the Northern Ireland Assembly. The voting experience is similar to how we vote under First Past the Post. Voters are presented with a list of candidates, but rather than placing a single X, the voter numbers the candidates in order of preference, with a number one as their favourite and so on.
Once the votes have been counted, a small group of the candidates become MPs. In our model, constituencies elect between three and six MPs each. All the MPs represent the whole constituency, so voters are free to contact any of them with their issues. A voter might contact the MP that represents their favourite party for instance or decide who to contact based on the substance of the issue.
Location of MPs for the largest parties
STV maintains a constituency link, while enhancing voter choice and leading to much more proportional outcomes than FPTP. Under STV, each voter still has one vote, but if a voter’s preferred candidate has no chance of being elected or has enough votes already, their vote can be transferred to another candidate according to their preferences. Voters can rank as many or as few candidates as they like.
This means that very few votes are ignored when compared with FPTP. It also ensures maximum voter choice, as electors can rank their choices both within and between parties and independents.
The Additional Member System
Additional Member System (50:50)
Voters in Scotland, Wales and London will recognise the Additional Member System, which has been in use for over two decades for the Scottish and Welsh Parliaments and the London Assembly.
Voters are given two ballot papers: one contains a list of candidates who want to represent the constituency, the other represents a list of parties who are trying to win representation in the local region or nation. Voters simply place a X by a candidate and a second X by a party.
A single MP is elected to represent the constituency and a bigger group represent the region or nation. Voters can contact their constituency MP, or they can contact one of the regional MPs.
The Additional Member System (AMS) – also known as Mixed Member Proportional Representation (MMP) outside of the UK – is a hybrid voting system. List seats ‘top up’ and partially compensate for the disproportionality associated with the FPTP element of the system, by taking into account how many constituency seats have already been won by a party.
For example, in our first AMS model the Green Party has only won a single constituency seat in the South East of England, yet they won a substantial amount of votes across the whole region. By our calculations they would win a further 11 seats at the regional level to make their overall representation in line with voters’ wishes.
In our first AMS projection, we have almost equal numbers of constituency and regional MPs (322 constituency MPs and 310 ‘List’ MPs). However, the design of AMS systems can differ quite considerably. One significant difference is the ratio of constituency to list seats, which has consequences for the proportionality of this voting system.
Additional Member System (68:32)
Our second AMS projection gives greater weight to the constituency seats with those seats making up 68% of the available seats. The top up seats make up only 32%. This means the final results are less proportional than the 50:50 model. However, it is not uncommon for AMS systems to have a different number of constituency and list seats. In Scotland 73 MSPs are elected in constituencies and 56 in regions (7 per region) (57:43) and when used for the Senedd, the AMS ratio was 40 constituency and 20 regional list (67:33).
Our 68:32 AMS projection, by giving a greater weight to the constituency seats, is closer to the FPTP result with Labour doing well in the constituency seats, as they did under FPTP in the actual election.
However, the top-up seats ensure that the overall outcome is a better reflection of voter choices than we saw at the election.
Labour are projected to get 54 more MPs under the 68:32 AMS system than under the 50:50 AMS system. Labour secure 43.4% of seats under the 68:32 system, which represents a 10-point bonus compared to the vote share they secured at the general election. Under the 68:32 system, the addition of either the Liberal Democrats or the Greens MPs would be enough to secure a Labour-led parliamentary majority, whereas under each of the other three PR systems, both the Liberal Democrats and Greens MPs would be required.
More broadly, a 10-point winner’s bonus, indicates that if a party received over 40% of votes at a general election, they would have a chance of getting a single-party majority under this system.
Party List PR
Party List Proportional Representation was used in Great Britain for twenty years to elect MEPs to the European Parliament and will be used at the next Welsh election to elect members of the Senedd.
In many countries where it is used, voters are presented with a long list of candidates either on a ballot paper or a poster in the polling booth. Voters can then mark their favourite. Parties will win seats in proportion to the number of people who voted for their candidates, with the individual candidates taking up the seats in order of their popularity.
With larger areas, voters have a broad choice of MPs they can approach for help, so most voters will have at least one MP from the party they voted for.
List PR systems vary depending on whether voters cast their vote for a party (closed list) or can vote for their preferred candidate within a list (open list).
Unfortunately, when it has been used in the UK, voters have been presented with just a list of parties. Rather than giving voters the full list of candidates, parties decide internally which candidates take up the seats.
List PR systems score highly in terms of proportionality, but – especially in the closed list variant – they limit voter choice, because electors are forced to vote for a list pre-determined by a party and cannot nuance their choice by ranking candidates, as in preferential systems. Though the open list variant can increase voter choice, there is often a weaker constituency link in List PR systems as voters elect a slate of candidates from a larger area than under other electoral systems. Reducing constituency sizes might improve local representation, but this would then affect proportionality.
Appendices
Methodology
Projecting how results of First Past the Post elections would translate into seats under different electoral systems is an imperfect task. Using such results as a baseline means that any projection still incorporates FPTP’s deficiencies – such as tactical voting considerations and the lack of genuine multi-party competition – which would not be the case under more proportional systems.
There are some ways to mitigate against these restrictions to ensure that projections account for potential changes to voting behaviour under PR systems. We commissioned a post-election survey from YouGov to ask how people would have voted if they had been allowed to rank parties in order of preference.
Single Transferable Vote (STV) methodology
For our STV projection, it was necessary to work on the basis of new constituencies. These have been created by aggregating existing FPTP constituencies into new three- to six-member seats. Single seat constituencies were used for three island seats (Orkney & Shetland; Na h-Eileanan an Iar; Ynys Mon) and a two-seat constituency was used for the Isle of Wight. For the single-seat constituencies, an Alternative Vote calculation was done to determine the winner.
Parties’ votes were added up and their vote shares were calculated for each of these STV constituencies. We then recalculated each party’s vote share in an STV constituency on the basis of first preference results in the YouGov poll. This meant that, for example, if 90% of those who voted for the Conservative Party in London ranked the party as their first preference in the poll, then 90% of Conservative votes in that region were assumed to be a first preference. This was done by region, meaning that the same ‘rejigged’ formula was applied to each STV constituency in an existing government office region.
We then proceeded to allocate seats using the droop quota, which means that, to win a seat, a candidate must receive a vote equivalent to the total number of votes cast divided by the number of seats to be allocated plus one. For example, in a three-seat constituency, the droop quota is equivalent to 25 percent. Any party which reached the quota was allocated a seat. Seats were awarded on the basis of how many quotas of support (e.g. combinations of 25%) a party won. So, a party winning 50 percent of the vote in a three-member constituency was allocated two seats.
If no party achieved the quota, the party with the lowest vote share was eliminated and its vote share was redistributed to other parties using a formula based on the second preference results in the poll. This process continued until all seats were allocated. In limited cases when awarding the final seat, no party reached a full quota so the party with the highest vote share was awarded the seat. Also in a limited number of cases, third preferences were used to help assign the final seat in a constituency.
This modelling is of course only an approximation of the allocation of seats and transfers under STV and relies on a limited number of preferences. But it does give an indication of how votes would transfer under STV and offers an insight into how voters’ choices would be translated into seats.
Additional Member System (AMS) methodology
AMS combines First Past the Post and List PR seats. The calculations used for our AMS projections thus involved a two-step process.
First, we allocated constituency FPTP seats. For the approximately 50:50 ratio of constituency to list seats, new AMS constituencies were created by combining two existing FPTP seats into a single AMS constituency. In some cases, because of an odd number of seats in a region, tricky geography or special exemptions, single FPTP constituencies were kept. We added up a party’s total votes and calculated their new vote share in each AMS constituency. As these seats are allocated under FPTP, the party with the most votes in each constituency was the winner.
Second, we allocated list seats on the basis of regions. We recalculated parties’ vote shares on the basis of voters’ first preference results in the YouGov poll by region. These ‘rejigged’ vote shares allowed us to recalculate the total votes each party received in that region.
We then used the D’Hondt formula to allocate seats to each party, based on the votes per region. We applied a five percent electoral threshold to each region and, as list seats are compensatory, we took into account how many seats each party obtained under the FPTP element to calculate the number of list seats to allocate.
Additional Member System (AMS) 68:32
For the AMS model with a 68:32 ratio of constituency to list seats, a different methodology was applied. We used smaller regions than those that were used for the AMS 50:50 model and we tried to use areas reflective of historic geographic units, such as English counties. The number of FPTP constituencies within these smaller areas were calculated and then of these, approximately two-thirds of the total FPTP seats within a region assigned to be FPTP seats and approximately a third assigned as top-up seats. For example, if there were ten FPTP seats in area, for the purposes of our AMS 68:32 model, there would be seven FPTP seats and three top-up seats.
The use of smaller geographic areas, with historic resonance, is another example of a trade-off. Voters may well feel closer to their ‘top-up’ representatives than under a system where larger geographic areas are used but the use of smaller areas (and fewer MPs per area) is likely to result in a less proportional overall result.
Full Results
Party |
Votes% |
Votes |
MPs |
MPs% |
Votes Per Seat |
Labour |
33.7 |
9,708.816 |
411 |
63.2 |
23,622 |
Conservative |
23.7 |
6,828,726 |
121 |
18.6 |
56,435 |
Liberal Democrat |
12.2 |
3,519,214 |
72 |
11.1 |
48,877 |
Scottish National Party |
2.5 |
724, 758 |
9 |
1.4 |
80,528 |
Sinn Féin |
0.7 |
210,891 |
7 |
1.1 |
30,127 |
Reform UK |
14.3 |
4,117,610 |
5 |
0.8 |
823,522 |
Democratic Unionist Party |
0.6 |
172,058 |
5 |
0.8 |
34,411 |
Green Party |
6.7 |
1,934,804 |
4 |
0.6 |
485,951 |
Plaid Cymru |
0.7 |
194,811 |
4 |
0.6 |
48,702 |
Social Democratic and Labour Party |
0.3 |
86,861 |
2 |
0.3 |
43,430 |
Alliance |
0.4 |
117,191 |
1 |
0.2 |
117,191 |
Ulster Unionist Party |
0.3 |
94,779 |
1 |
0.2 |
94,779 |
Traditional Unionist Party |
0.2 |
48,685 |
1 |
0.2 |
48,685 |
The Speaker |
0.1 |
25,238 |
1 |
0.2 |
25,238 |
Workers Party of Britain |
0.7 |
210,252 |
0 |
0 |
N/A |
Others |
2.8 |
805,102 |
6 |
0.9 |
134,183 |
You can see the difference between the share of the vote and the share of MPs in parliament for each party.
Thanks
We’d like to thank the following for their kind donations towards this report:
Peter Richell, Allan Mackenzie, Vicky Seddon, Alan Pavelin, Arvind Sivaramakrishnan, Richard Martin, Jenny Tonge, John Murphy, Rosalind Kent, Bill Davy, Stuart Dove, George Porter, Simon Balfre, Rod Hickey, John Birtill, Laurence Elton, Christopher Jones, David Croome, Richard Burnett-Hall, Martin Blake, Geof Butterwick, Anne Orchardson, Erik Williams, Malcolm Crook, Daniel Kelly, Jim Mccallum, David Dyter, Daryl Bass, Anthony Crellin-Whitty, David Martin, John Brown, Mark Rust, Mark Garland, Roger Banister, Dominic Cowen, Steven James, Darina Angelova, Sue Webber, Mike Fawcett, Wilhelm Skogstad, Michelle Fiorentini, Howard Orman, Timothy Pearce, Rosalind Stroud, Glyn Bradley, Rachel Dineley, Steven Caulfield, Roger Colkett, Fiona Mcowan, Patrick Newmarch, Catherine Brown, Gary Thomas, Pat Hotson, Matt Thompson, Neil Bradley, Malcolm Morrison, Michael Rozdoba, David Symonds, Cliff Howell, Paul Amundsen, Stanislav Domaratsky, David Gilbey, Graeme Hobbs, Harry Mcaulay, Robyn Pender, Colette Reap, Alan Tullo, Margaret Hallett, Norman Sanderson, Anthony Walmsley, Denise Taylor-Roome, Ross Sargent, Alan Egglesden, Alec Ward, Michael Clarke, Frank Graham Wilson, Sylvia Dunn, John Caldicott, Roger Lallemant, Bob Tench, Philip Pham, Peter Bungay, Lucy Conder, Peter Clough, Ian Shuttleworth, Tim Allen, Craig Mcdermott, Tim Pitt, Denise Dove, David Guest, Clive Patrick Till, Celia Harris, Ted Vine, Kerry Bown, Alan Dellard, Dennis Bate, John Gillbard, Sharon Belcher, William Dickson, Kevin Oneil, John Connor, John Fountaine, Mary Corin, David Hannaford, David Carroll, Colin Treby, Heather Foxton, Anthony Polatajko, Shirley Whiteside, Mike Loveland, Chan Abraham, Shaun Ferguson, Kevin Woods, Kathryn Keable, Annette Williams, John Martin, Craig Eastham, Trevor Adams, Steve Taylor, Geoffrey Starling, Mandy Gulatar, Martin Gledhill, Bob Dickson, Mavis Hibben, Ken Bourne, James Shorthouse, Rodney Lund, Stephen Ellice, Elizabeth Bancroft, Peter Arnett, John Lewry, Hamer Fernando, Graham Hewitt, David Adaway, Peter Cain, Paul Butcher, Mark Petersen, Jim Richards, Steve McFarlane and Lionel Barnes.