Climate activists are putting their weight behind a claim New Zealand has broken its climate change promises in the free trade agreement with the European Union.

They say the complaint is not an attack on New Zealand's exporters, workers or communities, but a call for the government to "explain its conduct and to take corrective action."

It comes as Trade Minister Todd McClay and the Green Party trade barbs over the issue.

A Dutch organisation lodged the first complaint of its kind through the European Commission's complaints mechanism known as the Single Entry Point.

It claims New Zealand had failed to uphold its legal commitments in the EU-NZ FTA not to weaken environmental protections in order to "encourage trade or investment," and to effectively implement the Paris Agreement.

The most extreme consequences could be losing access to the lucrative European market, but the group is seeking compliance rather than the suspension of trade benefits.

Climate campaigner and co-sponsor Mike Smith told RNZ the complaint was not an attack on exporters, workers or communities.

"It's more a call for the government to explain its conduct and to take corrective action.

"As Māori, we've got a sacred duty to protect the natural world for future generations. And when the domestic avenues for accountability are closed, we'll seek that accountability wherever we can."

Smith's case against major emitters was affected by a law change preventing companies from being sued over damage caused by greenhouse gas emissions.

He said the government cannot enjoy the benefits of the FTA while treating the commitments it made under that agreement as "optional."

Smith said it was "embarrassing" for New Zealand to be "first cab off the rank" in terms of these complaints, given it negotiated the deal.

Eliza Prestidge-Oldfield is a senior legal researcher at the Environmental Law Initiative, an organisation that is co-sponsoring the complaint.

She said the government had not recognised there was a strong link between "domestic climate action and international trade policy."

"So this is the first time there's been this sort of situation arise where a government has gone so far backwards on climate, and there is this path to accountability."

She said she would definitely rather New Zealand not be the test case. "It's a bit awkward."

She told RNZ "non-regression" meant "you can't go backwards on climate to try and encourage trade and investment."

The complaint recognised the "cumulative impact" of a whole lot of things across the climate change and environmental protection space over the last three years, she said.

Taken together, they show the government trying to facilitate more extractive industry investment in those sorts of industries, "at the expense of upholding those international climate change commitments."

Executive director of Greenpeace - also a co-sponsor - Dr Russell Norman said it was a big deal for New Zealand to come under fire for this and the agreement was significant because it potentially had teeth.

"If New Zealand were found to be in breach of the environmental chapter, then potentially some of those trade preferences could be rolled back.

"That's meant to be the discipline that ensures that the signatures to the agreement actually live up to their promises."

It was important for everyone on the planet there was strong climate policy and environmental protections, he believed, and that "we don't have trade resulting in a race to the bottom on environmental standards."

Norman also noted the government had been warned, but "carried on", saying finally the "chickens have come home to roost."

Trade Minister ‘disappointed’

Trade Minister McClay told RNZ he was deeply disappointed to see New Zealand organisations and the Green Party joining with foreign actors to attack New Zealand.

"This harms our exporters and the jobs they provide."

He said New Zealand took its international obligations seriously and "always meets them," maintaining the country was compliant with the FTA.

"This is the second time in a number of months that overseas groups and the Green Party have joined together to attack New Zealand and our exporters," McClay said, referencing a letter from the Greens raising their concerns in June.

"The first was a complaint to the European Commission, which was rejected. It shows why they are not fit to be in government, let alone to hold the Treasury benches.

"We have always been clear that we are committed to meeting our environment and climate obligations.

"However, it is for the New Zealand Parliament and our government to decide how we do this.

"It is not for overseas countries, organisations or lobby groups to tell New Zealand how to meet its obligations."

Wake-up call, say Greens

Green Party Co-leader Chlöe Swarbrick fired back, saying it should be a "wake-up call to the Minister."

She said McClay "knows that his government has undermined climate action and our international commitments. That comes with consequences."

The complaint was laid by a European organisation and the Green Party was not involved, she said.

"Two of the three current coalition parties are explicitly campaigning to pull out of the Paris Agreement, and National is behaving as if signing up to it doesn't mean doing anything.

"Their lack of seriousness on climate is obvious to everyone.

"This should be a wake-up call to the Minister to do his job, instead of blaming everyone else for the consequences of his actions."