Greens make a triumphant return to Parliament

The Green Party faced political oblivion, but has returned triumphant to Parliament, with ministerial positions for the first time.

Before the election, there were fears they wouldn't meet the 5 percent threshold for parliamentary representation, but now they'll support a Labour-NZ First Government.

Co-leader James Shaw was all smiles on Thursday night, calling the agreement "an historic moment for the Green Party and for our movement".

It's historic, because for the first time in its 27-year history, the party has ministerial positions, although they will be outside cabinet.

Greens delegates ratified the confidence-and-supply agreement with the Labour-NZ First Government late last night.

Almost all the 155 delegates supported the move.

"They've got our back, they've pretty much talked out every possible permutation of what it could look like," said Mr Shaw. "We've got the outcome we're looking for."

It's perhaps even more of an achievement, given how low they fell in the polls, dipping to 4.9 per cent in the Newshub Reid Research poll on September 12.

A benefit fraud confession by former co-leader Metiria Turei put the party into freefall, but Mr Shaw brought them back from the brink.

The Greens ended up with 6.3 per cent, returning eight MPs to Parliament.

An understandably proud Mr Shaw extended a hand to Winston Peters on election night, while on Thursday night, Mr Peters insisted that he'd never said a bad word about the Green co-leader.

Mr Shaw hasn't met with either Prime Minister-elect Jacinda Ardern or Mr Peters sinceThursday's announcement, but he won't have to wait long.

All three leaders will gather on Tuesday to sign documents that will make the new government official.