Election 2026: You’ve heard a lot about an overhang. What does it mean?
Much of this election campaign has been dominated by discussions of overhangs and vote-splitting. How does it work and what is it intended to cause?
An overhang is prompted if a political party wins more electorate seats than its share of the party vote entitles it to, which impacts the proportionality in the 120-seat House.
For example, if a party wins 10% (therefore entitled to 12 seats in the House) but wins 14 electorates, that party must have 14 seats. The House must then grow by two seats in order to afford the other parties their due proportionality, presuming no other parties were in a similar position.
That’s relevant when it comes to forming a government. The more seats a party or a bloc holds in a larger House makes it more likely they can form a majority in the House.
Overhangs have happened before but what has made this election unique is the very public, intentional campaigns to prompt an overhang in the hope of forming the next government.
This has been seen on both sides of politics. On the left, Te Pāti Māori ran a candidate-vote-only campaign, telling supporters to give their party vote to another party. That strategy aims to drive down Te Pāti Māori’s party vote to create a larger overhang, which depends on how many seats the party wins.
On the right, National has been at the centre of a vote-splitting campaign but not of its own volition. Prominent right-leaning figures, including former National and Act leader Don Brash, called on National supporters who want to see a re-elected coalition to split their vote, giving their electorate vote to the National candidate but their party vote to Act or New Zealand First.
In theory, that approach drives down National’s party vote and increases the seats it wins, thus engineering an overhang and increasing the odds of re-election. However, it does rely on enough people following the likes of Brash’s advice.
Christopher Luxon repeatedly warned his supporters against vote-splitting, even employing former leader Sir John Key to endorse the message. While the strategy could led to re-election, it would mean a thoroughly depleted National Party which could command a smaller share of power in coalition negotiations as a result.
It would also mean the party would have no list MPs; those who don’t run in an electorate or don’t win theirs. With a party vote share smaller than the number of electorates won, no MPs would come in on the list, meaning Finance Minister Nicola Willis would be gone, as well as Speaker of the House Gerry Brownlee.
Also at risk were senior MPs Chris Bishop and Paul Goldsmith who faced uphill battles to win their respective seats.
Ultimately, it won’t be until the preliminary and then official counts are returned when we will have an idea as to whether the public listened to the calls to vote strategically.
Adam Pearse is the Deputy Political Editor and part of the NZ Herald’s Press Gallery team based at Parliament in Wellington. He has worked for NZME since 2018, reporting for the Northern Advocate in Whangārei and the Herald in Auckland.