Rejected petition Require MPs who defect to another party to face a by-election.

Require legislation so that when an MP defects to another political party during a Parliament they must seek a fresh mandate through a by-election. This would protect voter trust, prevent unapproved shifts in representation, and ensure democratic legitimacy.

More details

When an MP switches party mid-Parliament, voters may end up represented by a party they did not choose. Many people vote based on party, manifesto and leadership, not just the individual. Defections can therefore erode trust and alter the political balance without consent. Requiring by-elections for party defection would give constituents a democratic say and help maintain legitimacy and accountability in our parliamentary system.

This petition was rejected

Why was this petition rejected?

There’s already a petition about this issue. We cannot accept a new petition when we already have one about a very similar issue.

You are more likely to get action on this issue if you sign and share a single petition.

You may wish to sign the following petition, which calls for similar action:

By-elections to be called automatically when MPs defect to another party
https://petition.parliament.uk/petitions/737660

We only reject petitions that don’t meet the petition standards.

Date submitted 19 January 2026
Get petition data (json format)

About petition data

The data shows the number of people who have signed the petition by country as well as in the constituency of each Member of Parliament. This data is available for all petitions on the site. It is not a list of people who have signed the petition. The only name that is shared on the site is that of the petition creator.