The Green Party has launched a petition urging the new government to not restart offshore oil and gas exploration.
The coalition government has promised to repeal the ban on exploring for new oil and gas reserves off the coast of New Zealand.
Green Party co-leader James Shaw said reversing the ban introduced in 2018 would be unscientific and dangerous.
"The vast majority of New Zealanders actually want our government to do more on climate change, not less," Shaw said.
"The simple fact is you cannot stop the climate crisis by burning more fossil fuels."
New oil and gas drilling in New Zealand seas was not needed to provide enough energy, he said.
Sustainable technology, such as using solar power from people's home for the general power supply, was a better option, he said.
It would take about 10 years for any new oil or gas supplies to be available, by which time less gas would be needed, because sustainable energy would have developed further, Shaw said.
The Green Party was concerned about other aspects of the environmental policies agreed by National, ACT and NZ First, such as weakening protections for fresh water, Shaw said.
"There's quite a lot in those agreements that we're very worried about and we will, of course, take our power role as the loyal opposition to challenge the government on those points."
Oil and gas lobby group Energy Resources Aotearoa supports repealing the ban on new oil and gas exploration in New Zealand waters.
The group's chief executive John Carnegie said more gas was needed, because there was a risk of an energy shortfall in New Zealand.
"We have an energy system on the edge of freefall. We've got risk factors stacking up. We've got Transpower on what seems to be a weekly basis issuing customer advice notices saying 'we've got a potential of generation shortfalls'.
"We've got a dry weather system pattern on its way. We've got rising energy prices. And we've got inadequate investment in backup generation for when there's no wind and rain.
"In this context, removing the ban is an unequivocally positive thing, because it will encourage more gas and more gas means a more diverse, affordable and reliable energy system," Carnegie said.
The group supported the goal of net zero carbon by 2050 "but we have to be realistic and pragmatic about how we get there and gas will have a role", he said.
"These renewables, yes we think that we need more renewable electricity and sources of energy but I'm sorry they simply can't deliver secure, reliable and affordable electricity.
"They're either not commercial at scale or they're incapable of filling the energy gaps when the wind doesn't blow and the sun doesn't shine," Carnegie said.
Using gas to produce electricity would ensure it was cheap and therefore could be used to help New Zealand remove carbon from transport, he said.