Luxon mulls referendum on New Zealand's mixed-member proportional voting system

Christopher Luxon announced his willingness to consider a referendum on New Zealand's mixed-member proportional (MMP) voting system, prompting critics to accuse larger parties of seeking a power grab. MMP, introduced thirty years ago to replace the British first-past-the-post method, obliges voters to cast two ballots—one for a local candidate and another for a party—resulting in a 120-seat parliament where the party vote determines overall seat allocation.

Since its adoption, governments have generally been coalitions, with the centre-left Labour or centre-right National partnering with smaller parties; the only exception was Labour's outright win in 2020. Minor parties like New Zealand First and Te Pati Māori have often acted as kingmakers, and the centrist Opportunity Party could become pivotal in the next election if it meets the 5 % party-vote threshold or secures an electorate seat.

The system also reserves seven seats for Māori electorates, and overhang seats can increase the total number of MPs, as occurred after the 2023 election when Te Pati Māora won six electorates with only 3.1 % of the party vote. Discussions about a referendum highlight ongoing tensions over whether MMP unduly favors coalition politics.