Green Party co-leader Marama Davidson says Labour's climate action pledges are too weak to meet the Paris target of limiting warming to below 1.5C.
And she has hit out at New Zealand First law and order policies, released today, calling them a desperate move by a low-polling party.
Today Labour leader Jacinda Ardern released the party's climate policies, which include replacing coal-fired boilers with electric alternatives, decarbonising the entire public transport bus fleet by 2035, and introducing a fuel-efficiency "clean car" standard.
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But despite Ardern citing price as a reason why people don't buy electric, Labour has dropped the feebate scheme - blocked this term by NZ First - which would have levied emissions-heavy cars to make emissions-light cars cheaper.
"Our view is that the clean car standard was where we should be investing our energy, and also you'll see today announcements around public transport and cleaning up that fleet," Ardern said.
Asked if Labour's climate policy was feeble, Davidson said: "It's encouraging they've announced one. That's good."
She said Labour's policies alone would fall short of meeting the Paris target.
"We are running out of time. Their policy is not going to meet the challenge at the scale it demands. That's why the Greens are needed.
"They want to phase out new dirty coal burners. Our minister [James Shaw] is already ripping them out of public hospitals and schools. We have to move quickly in the next 10 years to at least halve our emissions."
She said the feebate scheme was still party policy and it would be up to Green Party members to decide if it should be part of any potential Labour-Greens post-election coalition negotiation.
The Greens have stressed three priorities this election - climate change, biodiversity and inequality - and has released a $13.6b transport package to turbo-boost public transport within and between cities.
Greens co-leader James Shaw has recently called for left-leaning voters to party vote Green as the most strategic way to ensure Ardern has a second term, and Davidson said climate change was fertile ground for them to collect Labour voters.
"I hope people can see while the Labour plan is encouraging, we need the Greens," Davidson said.
"A vote for the Green Party is a vote for a stronger Labour government and is a vote to keep Judith Collins and David Seymour away from power."
Davidson also criticised the "punitive" law and order approach from New Zealand First, which today called for mandatory minimum sentences for "coward punches" - a policy it floated in 2016.
Davidson said re-releasing policy on minimum sentences "sounded like a low-polling party wanting to pull some desperate measures to get votes".
It's a similar sentiment to the Shaw's reaction of NZ First leader Winston Peters' recent Orewa speech in which Peters said many Māori were living in the past.
Ardern was also lukewarm on mandatory minimum sentences, saying the law already allowed judges to take aggravating factors into account to ensure an appropriate sentence.
She confirmed that Labour still wanted to scrap three strikes.
Davidson said making communities safer wasn't about getting tough on crime, but about healthy homes, adequate incomes, and access to mental health and addiction services.
"That is the way to reduce crime and reoffending to make sure our communities are safer and protected."