Hunch. Christopher Luxon has ruled out working with the Opportunity party, which said on 26 August it would work with either side, so talks could run long.
The cabinet market resolves on official government announcements at beehive.govt.nz: YES if by the end of 27 November, New Zealand time, new ministers are sworn in or the prime minister publicly names the new cabinet, and NO if neither happens. If the government site cannot be read, Guardian and BBC reports of the swearing-in settle it.
We looked for cases where New Zealand's governing parties faced voters under the system used since 1996, where seats follow each party's share of the vote. We found ten such elections, from 1996 to 2023. In six, a new cabinet was named or sworn in within 20 days of the vote. In the other four, talks took 32 to 65 days, and each time New Zealand First had the deciding seats. In most of the ten, the government side did not keep a majority on election night.