Rejected petition An immediate by-election to be called if an MP defects to another party.

A by-election after an MP defects is essential to democracy. Voters elect a party and its values, not just an individual. Changing allegiance breaks that mandate. A by-election restores trust, accountability, and gives constituents the right to choose their representation again.

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The government should introduce a clear legal requirement that any MP who defects from the party they were elected under must trigger an automatic by-election. This would protect democratic mandates, uphold voter trust, prevent political opportunism, and ensure constituents always have a direct say when their representation fundamentally changes.

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
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