‘The genie is out of the bottle’: The fight to fix MMP begins

This election’s 11-seat overhang (the largest in MMP's history) has done something no previous overhang managed: it has turned New Zealand’s electoral system into a live political question, Henry Oliver asks in today’s excerpt from The Bulletin.

We’ve had overhangs before, but never one like this. Parliament is set to grow to 131 seats – 11 more than its usual size – after Te Pāti Māori won five of seven Māori seats on 0.57% of the party vote and National won 42 electorates on a party vote entitling it to 35.

The result has moved MMP from the uncontroversial background of New Zealand politics to the centre of it. Some of the country’s leading constitutional experts are drafting an open letter, due next week, calling for a select committee inquiry into reform. According to Stuff’s Isaac Davidson, former National Cabinet minister Christopher Finlayson has described the system as “stuffed,” telling The Post that “a couple of billionaires have destroyed our system.” And Harry Mowbray, whose Split Your Vote campaign helped produce the National overhang, has told Newsroom he has no intention of stopping.

The academics behind the letter are not MMP’s critics but its defenders. As Newsroom’s Jonathan Milne reports, the signatories include Andrew Geddis, Lara Greaves, Jonathan Boston, Chris Eichbaum, Max Rashbrooke and Ralph Hall – people who have spent careers arguing that proportional representation delivered fairer parliaments and better consensus government.

Labour’s Kieran McAnulty wants a review beyond the routine post-election inquiries: “The genie is out of the bottle now and I suspect it’s going to be a feature of MMP moving forward unless changes are made.”

Act’s David Seymour was unmoved. “Ultimately, the vote belongs to the people,” he said. “Voters are entitled to use their two votes however they choose, and political parties should respect their decisions.” National said the usual Electoral Commission and Justice Committee processes would suffice.

What changed?

Overhangs are not new. There have been five before this one – 2005, 2008, 2011, 2014 and 2023 – and each added one or two seats. What makes 2026 different is scale and intent.

Milne identifies the key shift: previously, overhangs were inadvertent. Now they have been demonstrated as a tactic. Mowbray told him the right had wanted to do this for years but it hadn't been “palatable” – until Te Pāti Māori made it so.

“Because the Māoris made it palatable by going and taking the Harry plan and making it overt, now we're doing this,” Mowbray said. “That gave us the window to say, hang on, we didn't start this fight – but we'll continue it.”

The P in MMP

On TVNZ’s Q+A, political scientist Lara Greaves (who was part of a review of MMP in 2022 and was recently on an excellent episode of At Large with Toby Manhire) said the party vote “is meant to be the important one,” pointing to the P in MMP. This election, she said, “seems to be the biggest distortion of proportionality that we’ve had,” and she warned of a “circular tit for tat that's not actually going to serve what politics is about at all.”

Former National MP Nick Smith pushed back, defending the electorate vote as “grassroots democracy.” National won 41% of electorate votes, he said, far more than its 29% of party votes. Smith argued electorate MPs are forced to be more moderate and “need to be able to work across the political spectrum” – a quality he suggested a parliament focused purely on the party vote would lose. “If you’re looking for the perfect electoral system, it does not exist.”

Some options

Marcus Ganley, writing for Newsroom, sets out some options. The “German approach” would exclude electorate winners with the lowest vote share until parties fit their entitlement – denying seats to 11 MPs including Rawiri Waititi and Debbie Ngarewa-Packer, and leaving 11 electorates without a local MP. Compensation seats could restore proportionality but require a parliament of about 142 for National’s overhang alone, and nearly 800 to offset Te Pāti Māori’s.

Keeping parliament at 120 and cutting other parties’ list seats, as the 2012 and 2023 reviews recommended, fixes the size problem but not proportionality. A larger parliament with more list seats – Victoria University’s Jonathan Boston argues for 180 to 200 MPs – would absorb National’s overhang but not a manufactured one.

Jack Vowles, professor of political science at Victoria, told Stuff reform is now “essential,” tracing part of the problem to a ratio never adopted: the 1986 Royal Commission recommended 60 electorate and 60 list seats. Parliament went with 65 and 55, and uneven population growth has pushed it further out of balance – 72 electorates and 48 list seats by 2020.

“None of the options is without drawbacks,” Ganley writes. “But if we don't find a solution we can expect to see more of the same in future elections.”