UK Parliamentarians
- Keir MatherLabourMP for SelbyMP since 2023
- Brian MathewLiberal DemocratMP for Melksham and DevizesMP since 2024
- Baroness MattinsonLabourMember of the House of LordsPeer since 2025
- Lord Maude of HorshamConservativeMember of the House of LordsPeer since 2015
- Lord MawsonCrossbenchMember of the House of LordsPeer since 2007
- Baroness May of MaidenheadConservativeMember of the House of LordsPeer since 2024
- Alex MayerLabourMP for Dunstable and Leighton BuzzardMP since 2024
- Jerome MayhewConservativeMP for Broadland and FakenhamMP since 2019
- Charlie MaynardLiberal DemocratMP for WitneyMP since 2024
- Douglas McAllisterLabourMP for West DunbartonshireMP since 2024
- Lord McCabeLabourMember of the House of LordsPeer since 2025
- Kerry McCarthyLabourMP for Bristol EastMP since 2005
- Martin McCluskeyLabourMP for Inverclyde and Renfrewshire WestMP since 2024
- Lord McColl of DulwichConservativeMember of the House of LordsPeer since 1989
- Lord McConnell of GlenscorrodaleLabourMember of the House of LordsPeer since 2010
- Lord McCrea of Magherafelt and CookstownDemocratic Unionist PartyMember of the House of LordsPeer since 2018
- Dame Siobhain McDonaghLabourMP for Mitcham and MordenMP since 1997
- Lord McDonald of SalfordCrossbenchMember of the House of LordsPeer since 2021
- Andy McDonaldLabourMP for Middlesbrough and Thornaby EastMP since 2012
- Chris McDonaldLabourMP for Stockton NorthMP since 2024
- John McDonnellLabourMP for Hayes and HarlingtonMP since 1997
- Blair McDougallLabourMP for East RenfrewshireMP since 2024
- Lola McEvoyLabourMP for DarlingtonMP since 2024
- Pat McFaddenLabourMP for Wolverhampton South EastMP since 2005
- Lord McFall of AlcluithCrossbenchMember of the House of LordsPeer since 2010
- Alison McGovernLabourMP for BirkenheadMP since 2010
- Baroness McGregor-SmithNon-affiliatedMember of the House of LordsPeer since 2015
- Lord McInnes of KilwinningConservativeMember of the House of LordsPeer since 2016
- Baroness McIntosh of HudnallLabourMember of the House of LordsPeer since 1999
- Baroness McIntosh of PickeringConservativeMember of the House of LordsPeer since 2015
- Alex McIntyreLabourMP for GloucesterMP since 2024
- Gordon McKeeLabourMP for Glasgow SouthMP since 2024
Source: parliament.uk · 1,424 currently sitting · Open Government Licence v3.0