Election 2026: Herald-Motu Poll of polls suggests overhang, Opportunity could decide winner
Two unpredictable “O”s look likely to decide tomorrow’s election – Opportunity and overhang.
After six weeks of nonstop campaigning, neither the left nor the right bloc of parties will have enough party votes to secure a majority in Parliament, according to the Herald-Motu Poll of polls model.
The model works by running thousands of election simulations to calculate probabilities for likely outcomes.
It predicts both the Coalition of National, Act and NZ First and the combined vote of Labour, the Greens and Te Pāti Māori will fall short of an absolute majority. The graph below shows each party’s expected vote.
That leaves two wild cards, starting with Opportunity. Most polls suggest Qiulae Wong’s party could become the kingmaker for either side. The Poll of polls places Opportunity at 9%, higher than most polls – but even using a more conservative estimated poll average of 7.5%, the party still looks likely to make it over the 5% threshold and into Parliament.
Whether Opportunity then gets to play a role in government negotiations depends on the size of the overhang. National is expected to win more electorate seats than it receives from its party vote entitlement, forcing the creation of extra seats in Parliament (the “overhang”) and a whole new set of calculations.
The maths is complicated because Te Pāti Māori is also trying to engineer an overhang for the left and the outcome in some close electorates could affect the result.
The Poll of polls estimates National will lose three of its 44 electorate seats, giving it 41 seats, compared to its party vote share of 33. That would create an eight-seat overhang.
If the overhang prediction is correct, National could then join forces again with NZ First (14 seats) and Act (12) for a combined 67 seats. The Coalition would be over the 65-seat threshold in the 128-seat Parliament, without needing Opportunity to govern.
Small changes in both the party and electorate vote could change this outcome, but as a general rule a net overhang of eight or more seats to the right would probably put the Coalition back in power on the latest Poll of poll numbers. Anything less would require Opportunity.
Labour, the Greens and Te Pāti Māori need a higher party vote to win, even with Opportunity, as they don’t have enough electorate seats to engineer a similar overhang.
The model’s predictions are in this interactive. You can override them in individual seats and see how Parliament changes.
The model also puts the party vote difference between Labour and National at less than a percentage point – 27.7% for National versus 26.8% for Labour.
This combined “purple” party vote of 54.3% for the two major parties would be a record low, if repeated on election night.
Every poll since the Tax Payers Union-Curia poll in the first week of October put Opportunity above the 5% threshold needed to enter Parliament – and that October TPU poll had them just below at 4.8%.
The Poll of Polls model consistently estimates support for Opportunity higher than the polling average – it currently puts them at 8.9%. The model estimates today’s poll average is 7.5% and adds an extra 1.4% based on under-reporting by polls in the last three election cycles.
The polls are predicting the final party vote, once special votes are counted, so the results may differ from the election night count.
Chris Knox is a scientist turned investigative data-journalist who investigates the stories behind the numbers and creates interactives for Herald readers to explore them. He can be emailed at chris.knox@nzme.co.nz.