New Green Party co-leader James Shaw has used his first major speech to challenge the Prime Minister on climate change.
Mr Shaw addressed the party's annual meeting in Auckland, where he was elected yesterday to replace Russel Norman.
He said he did not support a formal coalition with the National Government, but was very open to working with National on common causes.
"We should talk to each other, not past each other. Let us find a common interest on climate change. That is my challenge to John Key."
Mr Shaw said he would focus on delivering on his co-leadership election promises, including doubling the party's membership by the end of this year and having more diverse representation.
Tributes paid to Russel Norman
Dr Norman announced he was stepping down from his role as the party's male co-leader in January.
He became the Green Party co-leader in 2006 and, after nine years in the job, said he had decided it was time for someone else to take over.
Speaking today in Auckland, he said he was disappointed the Greens did not make it into government at last year's election.
One of the party's founders, Jeanette Fitzsimons, who has also been at the party's annual meeting, praised the work of Dr Norman and said it was sad to see him go.
Mr Shaw also opened his speech by paying tribute to Dr Norman for the work he had done for the Greens.
He said he would endeavour to live up to Dr Norman's legacy and to continue to grow the party's vote.
He said, when Dr Norman became a co-leader, the party was hovering around the 5 percent threshold - and it was now the third largest party in Parliament.
New climate change campaign ahead of Paris
The party has started a new campaign calling on the public to implore the Government to take action on climate change.
In December, nations at an international climate conference in Paris will agree on a way to keep global warming below two degrees.
Dr Norman, who announced the campaign, said New Zealand had an opportunity to tell the world what was worth saving.
"It is a critical moment in human history. We're trying to stop the worst effects of climate change and this year is a very important moment to have our voices heard."
Dr Norman said the campaign would show the Government there was a meaningful public mandate for climate action.