Call a by-election when an MP defects or is expelled from a party. — 21 signatures. Status: rejected.
A UK parliamentary by-election happens when a seat in the House of Commons becomes vacant between general elections. This is either when an MP dies, is recalled via petition, convicted or joins the House of Lords. Yet they can change party or become an independent at a whim.
If an MP defects to another party or is expelled from a party or otherwise changes political affiliation from that that they were elected upon, this should trigger a by-election so that the people can give their say upon who they actually want to represent them.
View this petition on the official UK Parliament website