The Greens say they're confident of making it back into Parliament without Labour's help.
There's been speculation the two left-wing parties might cut a deal in Auckland Central, Labour urging its supporters to give their vote to the Greens' Chloe Swarbrick.
The electorate's current MP, National's Nikki Kaye, is leaving politics at the end of this term, and National is yet to name a new candidate. She's held the seat since 2008, but in four elections only managed to keep hold of the seat because the Greens and Labour candidate vote was split - if they'd done an ACT-National Epsom-style deal, the Greens or Labour could potentially have won it.
With the Greens polling right on the 5 percent threshold required to make it back into Parliament without an electorate, and coalition partner NZ First struggling in the polls, Swarbrick could be key to keeping the centre-left in power this September.
But the Greens appear unlikely to seek an arrangement.
"We think that Chloe can win on her own merits," party co-leader James Shaw told Newshub Nation on Saturday.
"She is an extraordinary candidate, she's got an enormous profile, she certainly has the highest name-recognition in that electorate. National don't even have a candidate there at the moment. We think she can win it, and we're throwing everything at it."
At this point in the election cycle in 2013, the Greens were riding high - polling at 13 percent, picking up a lot of estranged Labour voters.
But two things happened which derailed the Greens' campaign - then-co-leader Metiria Turei got caught up in two major scandals, and Labour installed Jacinda Ardern as leader. The Greens' vote collapsed, and they almost didn't make it back into Parliament, eventually scraping in with 6.3 percent, losing six MPs in the process.
"Ultimately the constellation of parties that make up the next Government is a result of the election," said Shaw, asked whether he'd be happy to work with NZ First again.
"That really is up to the voters of New Zealand... We have done an enormous amount in the last three years. Yes, there have been things we didn't get over the line - but in terms of the things that we did get over the line, we actually did get those things through as a result of our partnership with NZ First.
"It's not been comfortable at times - they have been a chaotic and disorganised partner in Government at times, but actually, you know, ultimately I think the people of New Zealand will judge what will make up the next Government. I'm pretty confident that we'll be in a position to form a Government with Labour."
"The Greens have shown we're a responsible, reliable partner that gets stuff done in Government - and that's only with eight MPs," added co-leader Marama Davidson.
"I'm really proud of what we have been able to get done... We are also very clear that we need to go further and faster, and that's why we are asking people to give us more support so we can be the progressive party that keeps pushing for the changes that we need."
Shaw said despite pundits claiming they've struggled to get much done thanks to NZ First's self-described "handbrake" on "woke pixie dust", that's simply not true.
"If you go through our confidence and supply agreement, we have made progress on virtually every single one. There are a couple of things we didn't get over the line and that is a disappointment - but in the round, we're really delighted with it.
"We've also got things over the line that weren't in our confidence and supply agreement, such as the ban on offshore oil and gas exploration. That wasn't in our confidence and supply agreement, but we still got it through in our first six months in office - so I would say our first term in Government has been a resounding success."
The party formally launches its campaign on Saturday afternoon, with the slogan "think ahead".
"We're not resting on any laurels anywhere," said Davidson.