Members of Tauranga iwi Ngāi te Rangi have been blocking commercial ships from leaving Tauranga Harbour's port to protest what they say is a secret deal between the Crown and Hauraki iwi.
Seven boats, including a waka taua, with about 42 passengers are stopping ships leaving the port.
Arrangements proposed for the Tauranga Moana Governance Group, as part of the Tauranga Moana Framework, would provide four seats for Tauranga Moana iwi, including Ngāi Te Rangi - as well as one seat for the iwi of Hauraki and five seats for local government representatives.
In 2004, the Waitangi Tribunal confirmed that the iwi of Hauraki had customary interests in the region's moana, particularly in the Te Puna-Katikati area.
Ngāi Te Rangi members said they were shocked to learn the Crown had agreed to give the Hauraki Collective some control in the city as part of a pending Treaty of Waitangi settlement.
They said they would not accept any Crown deal that gave Tauranga Moana rights to a collective of Hauraki iwi and hapū.
Ngāi Te Rangi iwi board chairman Charlie Tawhiao said these kinds of deals were fertile ground for fresh and contemporary claims here and across the country.
"A settlement agreement by Ngāti Whatua in Auckland is similarly undermining and changing tikanga Māori by the Crown, where those who have long left the area are returning again centuries later with ancient and pre-Treaty interests being puffed up into multiple claims for mana whenua."
Mr Tawhiao said the deal would mean engineering a completely new tribal structure in the area where three tribes - Ngāi Te Rangi, Ngāti Ranginui and Ngāti Pukenga - have held ahi kaa, or traditional and cultural jurisdiction.
"Ngāi Te Rangi has a case for urgency before the Waitangi Tribunal about this matter and any signing would be aimed at circumventing that legal process. It would be a case of the Crown trying to go around systems of examination that could shine light on what is really going on.
"If everything was above board, it would be transparent and not hidden."
No secret deal, minister's office says
Minister for Treaty of Waitangi Negotiations Chris Finlayson said no secret deal had been made.
"I think they are insulting Māoridom," he said.
"This is probably a pre-planned stunt and I am deeply unimpressed."
Mr Finlayson said a lot of work went into settling claims that cross those of other iwi.
"I have been trying to deal with overlapping claims with these people for some time and Charlie Tawhiao knows that full well."
Mr Finlayson said he had asked the iwi leaders forum to work with him to develop a cross claims process if they were not happy with what the Crown was doing.
Hauraki Collective leader Paul Majurey said he was suprised by the protest and said Tauranga Moana had known about the deal since 2014.
"All of the Tauranga Moana iwi were involved with that, in fact they agreed to that redress," he said.
"What appears to have occurred is that some of the current leadership and folk involved do not like what has happened previously and that is surprising given their close involvement with it."
Mr Majurey said the customary interests of Pare Hauraki within Tauranga Moana had already been recognised by the Waitangi Tribunal in their reports.
Ngāi Te Rangi is setting up a base camp on Matakana Island and further protest action is planned for the weekend.