A controversial bill banning future offshore oil and gas exploration has passed its third reading in Parliament - but the National Party has vowed to reverse it.

The Crown Minerals (Petroleum) Amendment Bill passed this evening with the support of Labour, NZ First and the Green Party, while National and Act opposed.

The bill followed a truncated public submission process and gives effect to the Government's announcement in April that it will cease offering new offshore oil and gas exploration.

Energy Minister Megan Woods said the passing of the bill was a line in the sand and represented a transition away from fossil fuels and towards affordable, renewable energy.

"New Zealanders want to see a future for their country where we take action on climate change ... where we have the courage to look beyond the three-year political cycle," she said, speaking at the third reading.

She noted that the bill preserves the rights of existing exploration permits, which cover an area of about 100,000sq km - roughly the size of the North Island.

"Those permit holders will have the same rights and privileges as before the law comes into force."

Greenpeace climate and energy campaigner Kate Simcock said the bill meant about 4 million sq km of the Earth's surface would be off-limits to oil and gas companies.

"And any deposits under our deep seas will stay in the ground where they belong."

The National Party's energy spokesman, Jonathan Young, said National would reverse the bill when it returned to power.

He lamented the lack of consultation and official advice before announcing the policy.

"When the minister was asked for evidence, for research, she was unable to present it," he said at the third reading.

"They did not seek analytical advice or information around the cost. They did not seek environmental evidence. They did not seek any consultation with the industry.

"All of the advice and analysis has come after the fact of the decision. It's an embarrassment."

Young said it was a "dark day" for the energy sector, and pledged that the next National Government would consult widely to reduce emissions, maintain business certainty, and minimise social disruption.