Waka-jumping

In New Zealand politics, waka-jumping is a colloquial term for when a member of Parliament (MP) either switches political party between elections (taking their parliamentary seat with them and potentially upsetting electoral proportionality in the New Zealand Parliament) or when a list MP's party membership ceases. The action is also called party hopping.

In 2001, legislation was enacted that required MPs to leave Parliament if they left their party; this law expired after the 2005 election. In 2018 a similar law was passed which requires a defecting MP to give up their seat on the request of their former party leader. Electorate MPs may re-contest their seat in a by-election, whereas list MPs are replaced by the next available person on the party list.

A 2013 Fairfax-Ipsos poll found that 76% of those surveyed oppose MPs staying in Parliament if they leave their party.