This list notes when a Member has changed allegiance from one political party to another or decided to sit as an independent MP. Instances of Members losing or resigning a party whip are also noted.
MPs' changes of party allegiance in the House of Commons since 1979 (210 KB, PDF)
No, by-elections are not automatically triggered if an MP changes his or her party affiliation although an MP may choose to stand down and fight the ensuing by-election under a new party label or as an independent Member.
Information on the role of the Government and Opposition whips in the management of parliamentary business can be found in the Commons Library briefing on the Whips’ Office.
This series of publications contains data on various subjects relating to Parliament and Government. Topics include legislation, MPs, select committees, debates, divisions and Parliamentary procedure.
Due to the difficulties in compiling a comprehensive list of all floor-crossings, whip withdrawals and whip resignations, this list cannot be guaranteed to be definitive.
We are always happy to hear of any additions or amendments to the list. Please email papers@parliament.uk with any comments.
We also welcome suggestions for new lists.
MPs' changes of party allegiance in the House of Commons since 1979 (210 KB, PDF)
A Westminster Hall debate on the 'Online abuse of elected women representatives' has been scheduled for Tuesday 21 April 2021 from 9.25-11.00am. The Chairman of Ways and Means appointed this debate on the recommendation of the Backbench Business Committee.
A list of Opposition Day debates since 1992 with information on debates and divisions on Opposition Day motions.
On 21 April 2021, there will be a debate on reports from the Committee on Standards concerning sanctions and confidentiality in the House’s standards system
