Excluded are the speaker, who traditionally stands for re-election without party affiliation, and MPs who were elected representing a major party but then defected or had the whip removed during a parliamentary term.
[citation needed] Minor party and independent MPs have been rare in recent times: there were only 13 people elected as such in Great Britain between 1950 and 2023.
However, there was a surge at the general election in 2024, with 4 Green MPs, 5 Reform MPs, and 5 independent candidates elected in constituencies with large Muslim populations, where there was opposition to the Labour Party due to their stance on the Israel-Gaza war.
Before 1885 it becomes increasingly difficult to identify which MPs were independent, and F. W. S. Craig's classification is used.
While these four are all currently regarded as major parties, each of these parties has at times held only a single seat (or none, in the cases of Sinn Féin, the SDLP, and the UUP), and for many years Sinn Féin was a banned organisation and did not contest elections.