Case Study: THE UK General Election 2024
A General Election was held in the UK on 4th July 2024 under the First Past the Post system (FPTP). The analysis below is based on data from the House of Commons Library.
For the purposes of this illustration, the speaker’s seat (Labour) is ignored. By convention other parties do not stand against that of the speaker (although in 2034, the Green party and three other small parties did). This skews the voting allocation of the elected parties. It would be better if the speaker’s seat were treated as a normal contest with the votes won being assigned to the party TVs. This means that voters in the speaker’s constituency would be treated in exactly the same way as other voters.
Under FPTP thirteen parties and six independent candidates were elected to 649 constituencies. Labour won 411 seats (63.33% of the 649). The total elected vote (TV) for the thirteen parties was 27,768,251 of which Labour had 9,708,716. This is 34.96% of the TV and, under PREVAIL, gives Labour a quota of 225 seats - considerably less than the 411 obtained under FPTP.
The table below shows FPTP results for the 643 party seats and the quotas under PREVAIL.
| FPTP | PREVAIL | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Party | Seats | Seats (%) | Elected Vote | Elected Vote (%) | Quota | Quota Type | FPTP Seats - Quota | Order of Parties for Transfer | |
| Totals | 643 | 100 | 27,768,251 | 100.00 | 643 | ||||
| Conservative | 121 | 18.82 | 6,828,925 | 24.59 | 158 | Under | -37 | Sixth | |
| Labour | 411 | 63.92 | 9,708,716 | 34.96 | 225 | Over | +186 | ||
| Liberal Democrat | 72 | 11.20 | 3,519,143 | 12.67 | 81 | Under | -9 | Fifth | |
| Reform UK | 5 | 0.78 | 4,117,620 | 14.83 | 95 | Under | -90 | Eighth | |
| Green | 4 | 0.62 | 1,943,813 | 7.00 | 45 | Under | -41 | Seventh | |
| Scottish National | 9 | 1.40 | 724,758 | 2.61 | 17 | Under | -8 | Fourth | |
| Plaid Cymru | 4 | 0.62 | 194,811 | 0.70 | 5 | Under | -1 | Second | |
| Democratic Unionist | 5 | 0.78 | 172,058 | 0.62 | 4 | Over | +1 | ||
| Sinn Fein | 7 | 1.09 | 210,891 | 0.76 | 5 | Over | +2 | ||
| Social Democratic and Labour | 2 | 0.31 | 86,861 | 0.31 | 2 | On | 0 | ||
| Ulster Unionist | 1 | 0.16 | 94,779 | 0.34 | 2 | Under | -1 | First | |
| Alliance NI | 1 | 0.16 | 117,191 | 0.42 | 3 | Under | -2 | Third | |
| Traditional Unionist Voice | 1 | 0.16 | 48,685 | 0.18 | 1 | On | 0 |
Of the main national parties only Labour is over quota with 411 FPTP seats against a quota of 225, an excess of 186 seats. The Democratic Unionist party with five FPTP seats is one over quota and Sinn Fein with seven FPTP seats is two over quota.
Two parties are on quota and eight are under quota. Of the latter, the Reform UK and Green Parties are the most significantly under quota.
The number of seats needing to be transferred from the three over quota parties to achieve perfect proportionality is 186 +2 + 1 = 189. The measure of disproportionality for FPTP is thus 100*189/649 = 29.12.
Percentage votes for the first party range from 70.57% down to 26.72%. There are 73 seats where the first vote exceeds 50%: Labour has 70 and Sinn Fein has 3. Percentage votes for the second party range from 42.73% down to 10.49% . Percentage votes for the third party range from 27.58% down to 4.49%. Percentage votes for the fourth party range from 19.52% down to 2.52%.
Four of the under quota parties required transfers only from seats in which they came second: Ulster Unionist, Plaid Cymru, Scottish National and Conservative. Three required transfers from seats in which they came second or third: Alliance NI, Liberal Democrat and Reform UK. The Green Party required transfers from seats in which it came second, third or fourth.
As spreadsheet giving details of the transfers will be available here shortly.
PREVAIL PLUS
The Workers Party of Britain party stood in 152 seats but did not win any. Their total vote was 210,252. This was more than obtained by six out of the thirteen parties that did win seats. The party came second in three seats and third in five. Their ten best percentages of vote range from 29.28 down to 10.3. Adding these ten percentages gives 176.51 which exceeds the threshold for PREVAIL PLUS. The Workers Party of Britain would therefore have been elected as a party without constituency. It is the only party to have achieved this in 2024.