Māori claimants are lining up to challenge the Trans-Pacific Partnership (TPP) in the Waitangi Tribunal.
An urgent inquiry will begin today and run all week in Wellington.
The Waitangi Tribunal will hear nine claims from more than 20 claimants, challenging everything from the consultation process to the deal's economic benefits.
The claimants will look to the tribunal to make an all-important call: will provisions in the trade deal protect their interests?
One claimant, Mana Movement leader Hone Harawira, said the answer was no.
"The TPPA is not in the best interest of Māori and it was not introduced in consultation with Māori."
Mr Harawira estimated fewer than five Māori would have seen the agreement before it was signed.
Another claimant, Mataatua District Māori Council chair Maanu Paul, said the government had overstepped its authority.
"I am saying that the government has no mandate to commit Māori to an international contract because Māori have never ceded their sovereignty to the Crown."
Mr Paul said he had expert witnesses, including economists who would "destroy the myth" that the TPP would provide huge economic gains.
"They have virtually plucked a figure from the air, cut it in half and said 'this is the benefit' which is full nonsense."
The government maintains its position that a special clause in the TPP preserves the Treaty of Waitangi and that nothing in it will prevent the Crown from meeting its obligations to Māori.
But Te Tai Tokerau District Māori Council chair Rihari Dargaville, another claimant, was not convinced.
"It is rhetorical ... The process that is going round now is merely really a consultation to show how economically well we will be off in the next 15-20 years. It is a matter of floating figures. There is no guarantee to that."
A challenge from the north
A majority of the claimants come from the north of the country.
Mr Harawira was not surprised, noting Ngāpuhi had earlier won a claim it had never ceded sovereignty to the Crown.
Ngāpuhi were not people to sit back and do nothing, he said - quoting the whakatauki (saying) "Ngāpuhi kowhau rau".
"Ngāpuhi of 100 holes - and within it, every hole has 100 chiefs and they stand up for the things they believe in," Mr Harawira said.
Even if the tribunal agrees with the claimants' cases, the Crown can choose to ignore the findings.
Last week, Treaty Negotiations Minister Chris Finlayson was asked if the Crown would make tribunal recommendations binding.
"I do not think the issue is binding/non binding," he said. "The tribunal occupies a special place in New Zealand both in terms of the work it does with historical treaty settlements, and I follow those all the time as a precursor to my negotiations with iwi, or on contemporary matters.
"We take careful notice of what they say. Whether we agree with everything they say is another matter."
This week's inquiry will be presided over by Judge Michael Doogan.
The tribunal panel will also decide what level of Māori engagement and input will be required for the ratification of the TPP to comply with the Crown's obligations under the Treaty of Waitangi.