Greenpeace executive director Russel Norman and climate activist Sara Howell will plead guilty to trying to obstruct an oil industry survey ship.
Former Green Party co-leader Norman and Howell swam in front of the Amazon Warrior as it searched for oil off the Wairarapa coast in April last year.
Greenpeace said today the pair would "plead guilty and seek a discharge without conviction, on the basis that their conduct was justified and necessary to bring about required change to government policy".
Norman said they would also make a plea for mitigation.
"On the grounds that our actions were reasonable and honourable given the threat of climate change, we remain hopeful that the Court will agree, given the importance of this issue," Norman said.
"Taking this route will also save supporter money and court time, and allow us to continue tackling climate change."
Greenpeace said the Ministry for Business, Innovation and Employment (MBie) planned to drop charges against Greenpeace, meaning the organisation will avoid up to $200,000 in fines.
Norman said the Amazon Warrior protest was part of an almost decade-long campaign to end fossil fuel exploration in New Zealand waters.
"We've just had a significant victory with that campaign," he said.
Howell said it had been encouraging to see how effective peaceful protest can be.
"I'm proud and humbled that I had the opportunity to contribute to an incredible, people-powered movement that's resulted in an end to new offshore oil and gas exploration permits," she said.
"I will take responsibility for what I did, [but] I believe it was necessary because all of the life on this planet - in its oceans, mountains, rivers, forests, and cities - is marvellous and brilliant. It is delicately balanced and too special to destroy."
Greenpeace, Norman, and Howell were due to appear in Napier District Court on Monday.
They will now appear by video link from Auckland District Court to lodge their pleas, and the case will be adjourned for sentencing on a date yet to be fixed.