The Greens could be part of a government that signs up to the controversial Trans Pacific Partnership trade agreement, co-leader Russel Norman has conceded.
His comments on TV3's The Nation this morning come ahead of nationwide marches against the TPP which are due to take place this afternoon.
The Green Party has been staunchly opposed to the TPP negotiations taking place behind closed doors. Dr Norman is due to address the Wellington protest against the trade deal this afternoon.
Asked on The Nation whether the Greens could be part of a government that signs up to the TPP, he replied: "Well, it could potentially, but it will depend on the votes on the day."
Dr Norman said the TPP would certainly be part of post-election negotiations with Labour.
The Australian Labor Party had called for the removal of the agreement's investor-state dispute clauses, which would allow multinational corporations to sue governments in international tribunals.
"So we'll be going to the New Zealand Labour party and we'll be saying, 'Look, if the Australian Labor Party can handle it, why can't you?'
"We'll be looking for what are the kinds of negotiated areas around the TPP so we that we can find a common ground."
A Green Party spokesman later clarified that the party continued to be opposed to the TPPA and would vote against it in its current form, whether in government or opposition. There would need to be significant changes to the agreement for the Greens to support it, he said.
Dr Norman said there were areas where the party could get Labour to move, but others where the parties would differ.
"So it will all depend on how that relative balance of power is in a post-election negotiation."
The TPP would have to change "very significantly" before the Greens would vote in favour of it.
"The current TPP is so far away from basic democratic rights, environmental protection."
Dr Norman was also questioned on whether the party could do a deal with Labour if the government supported deep-sea oil drilling or fracking - both of which the party opposes.
He said there were "a bunch" of policy areas where the Greens and Labour disagreed.
"We're standing up strongly to protect the environment and to avoid out-of-control climate change, and also to make the move to the smart, green economy, which is low-carbon.
"Now Labour is taking a different path, so somehow in the post-election negotiations, we're going to have to find a compromise that we can live with. And that's what politics is about, and that's what the voters demand of us."
The Green Party did not have a bottom line, like it did with the genetic engineering moratorium in 2002.
But there were issues the Greens stood for, and how much progress the party made would depend on the strength of the Green vote.
Dr Norman also admitted on The Nation that he had smoke cannabis.
"Yeah, yeah, of course I've smoked a joint," he said.
The decriminalisation of cannabis was still part of Green Party policy, but was unlikely to be one of the party's top 10 priorities, he said.