Votes versus seats

How first past the post turns votes into seats: each party's share of the vote and of seats, and the disproportionality of every election.

Gallagher index of disproportionality by election

2024 Gallagher index 23.7

Lab 33.7% votes → 63.2% seats
Con 23.7% votes → 18.6% seats
LD 12.2% votes → 11.1% seats
SNP 2.5% votes → 1.4% seats
SF 0.7% votes → 1.1% seats
Ind 2.0% votes → 0.9% seats
Ref 14.3% votes → 0.8% seats
DUP 0.6% votes → 0.8% seats
Grn 6.8% votes → 0.6% seats
PC 0.7% votes → 0.6% seats
SDLP 0.3% votes → 0.3% seats
APNI 0.4% votes → 0.2% seats
UUP 0.3% votes → 0.2% seats
TUV 0.2% votes → 0.2% seats
Spk 0.1% votes → 0.2% seats

2019 Gallagher index 11.8

Con 43.6% votes → 56.2% seats
Lab 32.1% votes → 31.1% seats
SNP 3.9% votes → 7.4% seats
LD 11.6% votes → 1.7% seats
DUP 0.8% votes → 1.2% seats
SF 0.6% votes → 1.1% seats
PC 0.5% votes → 0.6% seats
SDLP 0.4% votes → 0.3% seats
Grn 2.7% votes → 0.2% seats
APNI 0.4% votes → 0.2% seats
Spk 0.1% votes → 0.2% seats
Brx 2.0% votes → 0.0% seats

2017 Gallagher index 6.5

Con 42.3% votes → 48.8% seats
Lab 40.0% votes → 40.3% seats
SNP 3.0% votes → 5.4% seats
LD 7.4% votes → 1.8% seats
DUP 0.9% votes → 1.5% seats
SF 0.7% votes → 1.1% seats
PC 0.5% votes → 0.6% seats
Grn 1.6% votes → 0.2% seats
Ind 0.5% votes → 0.2% seats
Spk 0.1% votes → 0.2% seats

2015 Gallagher index 15.0

Con 36.8% votes → 50.8% seats
Lab 30.5% votes → 35.7% seats
SNP 4.7% votes → 8.6% seats
LD 7.9% votes → 1.2% seats
DUP 0.6% votes → 1.2% seats
SF 0.6% votes → 0.6% seats
PC 0.6% votes → 0.5% seats
SDLP 0.3% votes → 0.5% seats
UUP 0.4% votes → 0.3% seats
UKIP 12.6% votes → 0.2% seats
Grn 3.8% votes → 0.2% seats
Ind 0.3% votes → 0.2% seats
Spk 0.1% votes → 0.2% seats

2010 Gallagher index 15.1

Con 36.1% votes → 47.1% seats
Lab 29.0% votes → 39.7% seats
LD 23.0% votes → 8.8% seats
DUP 0.6% votes → 1.2% seats
SNP 1.7% votes → 0.9% seats
SF 0.6% votes → 0.8% seats
PC 0.6% votes → 0.5% seats
SDLP 0.4% votes → 0.5% seats
Ind 1.0% votes → 0.2% seats
Grn 1.0% votes → 0.2% seats
APNI 0.1% votes → 0.2% seats
Spk 0.1% votes → 0.2% seats
UKIP 3.1% votes → 0.0% seats

2005 Gallagher index 17.0

Lab 35.2% votes → 55.0% seats
Con 32.4% votes → 30.7% seats
LD 22.1% votes → 9.6% seats
DUP 0.9% votes → 1.4% seats
SNP 1.5% votes → 0.9% seats
SF 0.6% votes → 0.8% seats
Oth 5.8% votes → 0.6% seats
PC 0.6% votes → 0.5% seats
SDLP 0.5% votes → 0.5% seats
UUP 0.5% votes → 0.2% seats

2001 Gallagher index 17.9

Lab 40.7% votes → 62.5% seats
Con 31.7% votes → 25.2% seats
LD 18.3% votes → 7.9% seats
UUP 0.8% votes → 0.9% seats
SNP 1.8% votes → 0.8% seats
DUP 0.7% votes → 0.8% seats
PC 0.7% votes → 0.6% seats
SF 0.7% votes → 0.6% seats
SDLP 0.6% votes → 0.5% seats
Oth 4.0% votes → 0.3% seats

1997 Gallagher index 16.7

Lab 43.2% votes → 63.4% seats
Con 30.7% votes → 25.0% seats
LD 16.8% votes → 7.0% seats
UUP 0.8% votes → 1.5% seats
SNP 2.0% votes → 0.9% seats
PC 0.5% votes → 0.6% seats
SDLP 0.6% votes → 0.5% seats
Oth 4.5% votes → 0.3% seats
SF 0.4% votes → 0.3% seats
DUP 0.3% votes → 0.3% seats
UKUP 0.0% votes → 0.2% seats

1992 Gallagher index 13.6

Con 41.9% votes → 51.6% seats
Lab 34.4% votes → 41.6% seats
LD 17.9% votes → 3.1% seats
UUP 0.8% votes → 1.4% seats
SDLP 0.6% votes → 0.6% seats
PC 0.5% votes → 0.6% seats
SNP 1.9% votes → 0.5% seats
DUP 0.3% votes → 0.5% seats
Oth 1.3% votes → 0.2% seats

1987 Gallagher index 17.8

Con 42.3% votes → 57.8% seats
Lab 30.8% votes → 35.2% seats
Alliance 22.6% votes → 3.4% seats
UUP 0.8% votes → 1.4% seats
SNP 1.3% votes → 0.5% seats
SDLP 0.5% votes → 0.5% seats
PC 0.4% votes → 0.5% seats
DUP 0.3% votes → 0.5% seats
Oth 0.5% votes → 0.2% seats
SF 0.3% votes → 0.2% seats

1983 Gallagher index 20.6

Con 42.4% votes → 61.1% seats
Lab 27.6% votes → 32.2% seats
Alliance 25.4% votes → 3.5% seats
UUP 0.9% votes → 1.7% seats
DUP 0.5% votes → 0.5% seats
SNP 1.1% votes → 0.3% seats
PC 0.4% votes → 0.3% seats
Oth 0.8% votes → 0.2% seats
SDLP 0.5% votes → 0.2% seats
SF 0.3% votes → 0.2% seats

1979 Gallagher index 11.6

Con 43.9% votes → 53.4% seats
Lab 37.0% votes → 42.4% seats
Lib 13.8% votes → 1.7% seats
UUP 0.8% votes → 0.8% seats
Oth 1.6% votes → 0.5% seats
DUP 0.2% votes → 0.5% seats
SNP 1.6% votes → 0.3% seats
PC 0.4% votes → 0.3% seats
SDLP 0.4% votes → 0.2% seats

October 1974 Gallagher index 15.0

Lab 39.3% votes → 50.2% seats
Con 35.9% votes → 43.6% seats
Lib 18.3% votes → 2.0% seats
SNP 2.9% votes → 1.7% seats
UUP 0.9% votes → 0.9% seats
PC 0.6% votes → 0.5% seats
Oth 1.3% votes → 0.3% seats
VUPP 0.2% votes → 0.3% seats
SDLP 0.4% votes → 0.2% seats
DUP 0.2% votes → 0.2% seats

February 1974 Gallagher index 15.5

Lab 37.2% votes → 47.4% seats
Con 37.8% votes → 46.6% seats
Lib 19.3% votes → 2.2% seats
SNP 2.0% votes → 1.1% seats
UUP 0.7% votes → 1.1% seats
Oth 1.1% votes → 0.5% seats
VUPP 0.2% votes → 0.5% seats
PC 0.6% votes → 0.3% seats
SDLP 0.5% votes → 0.2% seats
DUP 0.2% votes → 0.2% seats

1970 Gallagher index 6.6

Con 46.4% votes → 52.4% seats
Lab 43.0% votes → 45.6% seats
Lib 7.5% votes → 1.0% seats
Oth 1.5% votes → 1.0% seats
SNP 1.1% votes → 0.2% seats

1966 Gallagher index 8.4

Lab 47.9% votes → 57.6% seats
Con 41.9% votes → 40.2% seats
Lib 8.5% votes → 1.9% seats
Oth 1.0% votes → 0.3% seats

1964 Gallagher index 8.9

Lab 44.1% votes → 50.3% seats
Con 43.4% votes → 48.3% seats
Lib 11.2% votes → 1.4% seats

1959 Gallagher index 7.3

Con 49.4% votes → 57.9% seats
Lab 43.8% votes → 41.0% seats
Lib 5.9% votes → 1.0% seats
Oth 0.6% votes → 0.2% seats

1955 Gallagher index 4.1

Con 49.7% votes → 54.6% seats
Lab 46.4% votes → 44.0% seats
Lib 2.7% votes → 1.0% seats
Oth 1.1% votes → 0.5% seats

1951 Gallagher index 3.0

Con 44.0% votes → 47.7% seats
Lab 48.9% votes → 47.5% seats
Nat Lib 3.7% votes → 3.0% seats
Lib 2.6% votes → 1.0% seats
Oth 0.5% votes → 0.5% seats
Ind Con 0.2% votes → 0.3% seats

1950 Gallagher index 7.2

Lab 46.1% votes → 50.4% seats
Con 40.0% votes → 45.1% seats
Nat Lib 3.5% votes → 2.7% seats
Lib 9.1% votes → 1.4% seats
Oth 0.5% votes → 0.3% seats

1945 Gallagher index 12.1

Lab 47.8% votes → 62.4% seats
Con 36.2% votes → 31.1% seats
Lib 9.0% votes → 2.0% seats
Nat Lib 2.9% votes → 1.8% seats
Oth 2.1% votes → 1.3% seats
ILP 0.2% votes → 0.5% seats
Com 0.4% votes → 0.3% seats
Nat Ind 0.3% votes → 0.3% seats
CW 0.4% votes → 0.2% seats

1935 Gallagher index 13.6

Con 47.7% votes → 62.7% seats
Lab 38.0% votes → 26.5% seats
Nat Lib 3.9% votes → 4.8% seats
Lib 6.7% votes → 3.4% seats
Nat Lab 1.4% votes → 1.2% seats
Oth 1.5% votes → 0.7% seats
ILP 0.6% votes → 0.7% seats

1931 Gallagher index 21.9

Con 55.1% votes → 77.2% seats
Lab 29.5% votes → 8.0% seats
Lib 7.0% votes → 5.8% seats
Nat Lib 3.0% votes → 4.3% seats
Nat Lab 2.1% votes → 3.1% seats
ILP 1.1% votes → 0.7% seats
Nat 0.6% votes → 0.7% seats
Oth 0.9% votes → 0.2% seats
Ind Lab 0.3% votes → 0.2% seats

1929 Gallagher index 12.4

Lab 37.2% votes → 47.1% seats
Con 38.1% votes → 42.2% seats
Lib 23.6% votes → 9.7% seats
Oth 1.0% votes → 1.0% seats

1924 Gallagher index 17.2

Con 46.7% votes → 66.4% seats
Lab 33.4% votes → 25.8% seats
Lib 17.8% votes → 5.9% seats
Const 1.2% votes → 1.2% seats
Oth 0.7% votes → 0.5% seats
Com 0.3% votes → 0.2% seats

1923 Gallagher index 3.6

Con 38.0% votes → 41.7% seats
Lab 30.8% votes → 31.5% seats
Lib 29.6% votes → 26.2% seats
Oth 1.4% votes → 0.7% seats

1922 Gallagher index 15.0

Con 38.6% votes → 56.8% seats
Lab 29.7% votes → 23.6% seats
Lib 19.0% votes → 10.3% seats
Nat Lib 9.8% votes → 8.0% seats
Oth 1.4% votes → 0.5% seats
Ind Con 0.6% votes → 0.5% seats
Ind 0.8% votes → 0.3% seats

1918 Gallagher index 16.5

Con 38.6% votes → 54.2% seats
Co Lib 13.0% votes → 18.0% seats
SF 4.6% votes → 10.5% seats
Lab 21.3% votes → 8.0% seats
Lib 13.0% votes → 5.2% seats
Co Lab 1.6% votes → 1.3% seats
IPP 2.1% votes → 0.9% seats
Oth 1.7% votes → 0.4% seats
Ind 1.5% votes → 0.4% seats
Lab U 0.3% votes → 0.4% seats
Ind Lab 1.0% votes → 0.3% seats
Nat 0.7% votes → 0.1% seats
Ind Lib 0.1% votes → 0.1% seats

Official results House of Commons Library and UK Parliament election results data. Contains Parliamentary information licensed under the Open Parliament Licence v3.0. How we use this data