Halfway through the election cycle and with polls pointing to a close contest next time, Audrey Young assesses the possible shape of the next Government.
The most important factor in forming coalitions or alliances to govern is the number of seats each political party wins in an election, but it is not the only factor, as New Zealand First knows.
It's complicated and options may be limited by some parties refusing to work with other parties, and can make that clear either before or after an election.
New Zealand First's pre-election position has varied from ruling out no one, ruling out everyone, and ruling out the Greens.
The Māori Party, which could hold the balance of power according to the last 1News Kantar political poll, has not ruled out working with any party.
But assuming New Zealand First campaigns at the 2023 election on a platform opposing Māori co-governance, it may well be on the basis that it would not enter any arrangement that included the Māori Party.
Of course, either or both parties could promise to sit on the cross-benches and not support any party on confidence and supply.
But even when parties don't want to work with certain others, there are ways for two smaller parties to have a formal relationship with the major party, and not with each other.
That was the structure of Jacinda Ardern's first-term government: a Labour–New Zealand First coalition with a confidence and supply agreement with the Greens.
There was no agreement between New Zealand First and the Greens, and Labour needed both.
Former Prime Minister Helen Clark in the last days of the 2002 election campaign ruled out working with New Zealand First after the election, and did a deal with the United Future Party.
After the 2005 election, however, it was a different matter. New Zealand First signed up to a confidence and supply agreement with Clark and Labour - with the proviso that the Green Party was not part of the governing arrangement.
It was the first general election contested by the Māori Party and beforehand, Clark had deemed it would be "last cab off the rank" in terms of preferred partners.
Labour gave Peters and United Future leader Peter Dunne ministerial posts outside Cabinet in return for confidence and supply agreements for Labour.
For extra comfort for Labour and some policy concessions for the Greens, the Greens negotiated an abstention agreement with Labour. That meant that on confidence votes, the worst it would do would be to abstain, not a negative.
National in opposition in 2008 ruled out working with New Zealand First after the election. That bottom line may well have influenced how people voted in the 2008 election and New Zealand First was voted out of Parliament for a term.
National was able to form a Government with support from its natural ally, Act, and United Future, but also invited the Māori Party to negotiate a confidence and supply agreement, despite not needing the numbers – Labour has done the same thing in the current arrangements with the Green Party, giving it ministerial posts despite not needing it.
Each of National's three support parties had ministers outside Cabinet, following the pattern of Labour's 2005 Government.
Before returning to Parliament in 2011, New Zealand First said it would not work with either of the major parties, but it was not needed anyway.
After nine years in power, National was back in opposition in 2017, and at the start of election year in 2020, it again decided to rule out working with New Zealand First.
New Zealand First again was voted out of Parliament altogether, although Covid-19 and National's leadership changes were major factors in Labour winning the first outright majority under MMP.
The Green Party and National have usually not ruled out the other party completely but have made it clear that the policy incompatibilities would make it virtually impossible.
You can safely assume National and Labour won't work together to form a government.
It is more likely than not that the Māori Party and New Zealand First will leave themselves open to working with others in the meantime but closer to the election could indicate a preference for the cross-benches and remaining detached.