The Government is caught up in a legal battle over the proposed removal of Maori fishing rights in the Kermadecs, 1000km northeast of New Zealand.
A new sanctuary in the area would see all fishing banned, despite a 1992 Treaty of Waitangi settlement giving all Maori customary and commercial fishing rights.
Just two iwi were consulted on the plans, and Labour MP for Te Tai Tonga, Rino Tirikatene, is appalled.
"These rights are ongoing and evolving. The Crown knows that, they've been caught out, they thought they could pull a swifty on Maori, and they clearly haven't done their homework and they haven't fulfilled their obligations as a good Treaty partner."
The Government's previously said Maori can fish elsewhere because the fish in the sanctuary are migratory species and will move to other parts of the ocean.
Appearing on the Paul Henry programme this morning, Prime Minister John Key said Parliament is "supreme" and can "pass whatever laws it wants".
"This is the single largest gift New Zealand's ever given, if you like, in environmental terms in the ocean. It's massive," he says.
"The argument always seems to me from Maori that they want to preserve the environment for their mokopuna, and here we are doing this thing which is enormous on a world scale."
Papers were filed in the High Court by the Maori Fisheries Trust late last week.
"These are customary rights based on the Treaty," says Mr Tirikatene. "Maori have a reasonable expectation to ensure that these rights exist and will be there for future generations."
Mr Key rejects criticism he should have consulted with more than just two iwi before making the proposal.
"We made the call on what we believe is, I think, a widespread view of New Zealanders that this is the right thing to do. Every single political party in Parliament voted for it. But look, people have the right to test things in court."
The plan covers 620,000 square kilometres in the northeastern corner of New Zealand's exclusive economic zone.