By convention, the membership of each select committee should broadly reflect the balance of parties in the House of Commons. However, as can be seen from Figures 1 and 2, this convention does not appear to have been thoroughly applied, both with regard to the overall membership of select committees and the membership of many individual select committees. The deviation is most notable with respect to the representation of Liberal Democrats and MPs from smaller parties. While Labour MPs are represented on select committees broadly in proportion to their presence in the wider House, Liberal Democrats are overrepresented, while MPs from a party other than the three largest parties are underrepresented.

Similarly, the October elections also left the Conservative Party underrepresented, but this is in the process of being resolved as the vacant places are taken up by their MPs (although they appear to have donated one of their two places on the Women & Equalities Committee to the former Labour and now independent MP, Rosie Duffield).

However, the underrepresentation of smaller parties will persist even once all the places are filled. With the exception of Plaid Cymru, no minor party has more than one MP among the places on all select committees. Reform UK are the only minor party with more than one MP in the House that has no representation on any select committee. Plaid Cymru, however, have three members on the Welsh Affairs Committee – 75% of the four Plaid Cymru MPs in the House.

As has been observed in previous Parliaments, female MPs are over-represented on select committees relative to their representation in the House. Whereas women make up 40.5% of all MPs, they account for 45.5% of select committee members.

Previous research on the UK Parliament has observed gendered divisions of labour when it comes to committee membership, with female MPs more likely to be members of what are often perceived to be less prestigious committees and/or committees which cover what might be regarded as stereotypically feminine policy areas. This latter tendency for women to be underrepresented on prestigious committees seems to have been weakening over time and, to a large extent, has disappeared in this latest Parliament. There is now no statistical evidence of a correlation between the prestige of a committee and the proportion of female members. This is mainly due to the dominance of Labour MPs on the committees and the decision by the Labour Party that women must make up at least half of their members on each committee. As shown in Figure 3, this means that female members are now more evenly spread across committees than has often been the case. Only the Petitions and Defence Committees have under 30% female representation and only the Education and Women and Equalities Committees have female representation above 70%.

MPs from an ethnic minority background are under-represented among select committee members when compared with their representation in the wider House, whereas they have been over-represented in recent Parliaments. Whereas ethnic minority MPs comprise 13.8% of all MPs, they comprise only 11.0% of committee members.

How ethnic minority MPs are distributed across specific committees is more in line with previous trends, although there appears to be some disruption to patterns seen in previous Parliaments. However, as with gender, there is no statistical evidence of a correlation between a committee’s prestige and the proportion of ethnic minority members on that committee.

Notable examples of committees that have broken with previous trends include:

• the Culture, Media and Sport and Defence Select Committees, where ethnic minority members tended to be absent or under-represented in previous Parliaments;

• the Home Affairs Committee, on which ethnic minority members have tended to be over-represented but where their presence is now proportionate; and

• the International Development Committee and the Public Administration and Constitutional Affairs Committee, on which ethnic minority members have tended to be over-represented, but where they are now absent.

The Welsh Affairs Committee is now the only House of Commons select committee, whose members are elected, that has never had an ethnic minority member.

Some commentators have noted the lack of regional representation on certain select committees. Figure 5 shows the number of regions represented by at least one member for each select committee, and Figures 6 and 7 provide a more detailed breakdown of the proportion of committee members from each of the 12 regions.

As you would expect, the Welsh and Scottish Affairs Committees are both dominated by MPs from the corresponding nation. However, there are potentially problematic patterns of regional representation on some of the departmental select committees:

None of the members of the Defence Committee or Treasury Committee represent seats outside of England. Between 1979 and 2016, members representing constituencies in Scotland, Wales or Northern Ireland constituted around 20% and 10% of the Defence and Treasury Committees respectively.

• Over a third of the members of the Treasury Committee are from London.

• Over 50% of the Business and Trade Committee represent seats in the Midlands, while none of the members represent seats in the North of England, East of England, London or Wales.

• None of the members of the Culture, Media and Sport Committee represent seats in the Midlands, South West, North East, or Yorkshire and the Humber. Since culture is a devolved matter, the lack of representation outside of England may be less concerning.

Much was made of those MPs from the 2024 intake who chose to stand in the elections of select committee chairs earlier this year. Similar to the outcome observed in those elections, where only one candidate from the 2024 intake was elected, how long an MP has spent in the House of Commons still seems to matter in some important ways when it comes to select committee membership.

Figure 8 shows the average number of years since members of each select committee first entered Parliament. The data shows that the committees with the most experienced parliamentarians are the Treasury, Foreign Affairs, Defence and Public Accounts Committees. The committees whose members have the least parliamentary experience are the Scottish Affairs, Transport, Public Administration and Constitutional Affairs, and Petitions Committees.

The ranking of committees by average experience highlights evidence of a moderate-to-strong correlation between the average length of time since a committee’s members entered Parliament and the prestige of that committee, suggesting that parliamentary experience may be important in determining the membership of more prestigious committees.

Figure 9 depicts the average electoral majority achieved by members of each select committee at the last general election As the chart demonstrates, members of the Foreign Affairs Committee have the largest average majorities, while members of the Business and Trade Committee have the smallest. Again, there is some evidence of a moderate positive correlation between the average majority among a committee’s membership and the prestige of that committee, suggesting that membership is not solely based on merit or experience.

This research is based on the composition of select committees at the point at which they were initially constituted. Since that time, several members elected to select committees in October 2024 have stepped down following the Conservative leadership election and several government reshuffles. Some committee members have already been replaced. All calculations used in this blog use the original membership of each committee with replacement members not being included.

The correlation between the average length of time since a committee’s members entered Parliament and committee prestige is r = 0.576, P < 0.01.

The correlation between the average majority among a committee’s membership and committee prestige is r = 0.452, P < 0.05.