Prime Minister Christopher Luxon has promised a referendum on the MMP electoral system if National is re-elected in the November election, alongside a separate referendum on extending the parliamentary term from three years to four.

Luxon told Newstalk ZB on Thursday morning that an MMP referendum is "something we should consider" and that he wants to see it happen next year. He also urged voters to vote for National on November 7 to avoid coalitions with parties that don't share his values or policies.

The announcement drew immediate fire from NZ First leader Winston Peters, who condemned the MMP referendum call as "inexplicable" and a "power grab." Peters posted on Facebook on Thursday praising the move from first-past-the-post to MMP for breaking the "stranglehold" of two parties, and saying the two old parties want to change the electoral system to favour their falling fortunes.

Labour leader Chris Hipkins rejected the need for a referendum, noting that the 2011 referendum on the matter showed people clearly favoured MMP, with 58 percent voting in support.

The pledges come against a long backdrop of electoral reform in Aotearoa. New Zealand's MMP system replaced the traditional first-past-the-post voting method after an indicative two-part referendum in 1992 and a binding referendum in which MMP received the support of 54 percent of voters. The system had been proposed by a Royal Commission. In the 1993 referendum, more than eighty percent of voters wanted to change the electoral system.

Luxon's own posture toward MMP has shifted over time. In a 9 September 2024 post-cabinet press conference, he said New Zealand operates within an MMP environment, that it was the system New Zealand voted for, and that a compromise was made. The Independent Electoral Review's final report, released in January 2024, had ruled out recommendations such as lowering the voting age to 16 and allowing all prisoners to vote and stand for election.

The broader context here is a governing relationship between National and NZ First that has been strained for months. Peters said in April that Luxon calling a confidence vote in his leadership "promotes doubt" and could invite further challenges. Peters has also declared NZ First poised for a "massive victory" at the 2026 election, criticising Labour, National and the Greens. NZ First has separately introduced a Member's Bill that would ensure a binding referendum on the Māori seats.

Luxon's pitch to voters — vote National on November 7 to avoid coalition partners who don't share his values — frames both referendums as part of an argument for single-party government. The two referendums would, if delivered, put the electoral system and the length of the parliamentary term before voters in the same cycle, reopening constitutional questions settled at the ballot box in 1993 and 2011. Whether that appeal lands with an electorate that has twice endorsed MMP, and whether the promise survives coalition negotiations after November 7, are the political questions now in play.