Kaumātua from Motiti Island in Bay of Plenty have been granted an urgent hearing in the Waitangi Tribunal.
The six elderly claimants are arguing that the small island's hapū are tangata whenua, and should get their own treaty settlement.
Earlier this month, the Waitangi Tribunal approved the application for the urgent hearing for next year.
Tribunal documents showed the Crown opposed the application under urgency and thought the Motiti hapū had benefited from the settlements for Ngāti Awa and Tauranga Moana.
Motiti Rohe Moana Trust chair and claimant Umuhuri Matehaere said the hapū have been treated unfairly by the Crown.
"Motiti has been ignored completely in terms of te whenua and te rohe moana.
"We are being told go and see your iwi, whether it is Ngāti Awa or whether it is Tauranga Moana - so we are that have been there for generations.
"If it doesn't come to light, then the hapū that we are from becomes extinct and there is no reason why that should be when it is still alive and in us."
The Motiti Rohe Moana Trust has taken a number of legal proceedings to try to protect the island's environment since the grounding of the Rena on Astrolabe Reef, near the island, in 2011.
It won a case in the Environment Court last year to set fishing restrictions, or a rāhui, over the reef.
But court action was not cheap, and it would only get more expensive as the decision had been appealed by the Ministry for Primary Industries and commercial fishers, Mr Matehaere said.
It had been opposition after opposition from the Crown and council, he said.
"In terms of resources, it is quite draining, and it has been. We don't have the resources."
The tribunal will hear the case - the Wai 2521 Motiti claim - next year.
It will decide if the Motiti hapū have been wrongly grouped in another settlement and if so, what impact that had on the island people and whether they should get their own settlement.
Claimants project manager Hugh Sayers said the hearing could not come soon enough for the kaumātua - some of who were in their late 80s.
"The sense of the claimants is that the Crown is dragging things out until they pass in the hope that these matters will go away.
"This is a stressful, difficult and complex process that they have had to engage in."
The appeal of the Environment Court decision in favour of the trust will be held in the High Court in Hamilton in May.