Māori health advocates are leading a bid to the Waitangi Tribunal to stop government plans to disestablish Te Aka Whai Ora, the Māori Health Authority.
The government plans to disestablish the authority in its first 100 days.
Lady Tureiti Moxon and the head of a Māori primary health organisation, Janice Kuka, have made a request for an urgent hearing regarding the government's plans on 8 December.
A Waitangi Tribunal document published on Thursday said they were making the request on behalf of governors, managers, staff and Māori cared for by Māori-owned primary health organisations.
Judge Damian Stone is considering the request and has given the Crown until the end of Monday to reply.
The Māori health authority was set up last year under health reforms, with the aim of giving Māori a greater say in their own healthcare and ending poorer health statistics.
Their Statement of Claim, lodged with the Tribunal, said disestablishing the authority would prejudicially affect Māori and force Māori health providers to continue operating in an overstretched and underfunded capacity.
There would no longer be a Māori body which aimed to create services to achieve the best possible health outcomes for Māori and promote Māori health.
They pointed out historic underfunding by the crown for Māori health providers and primary health organisations (umbrella groups comprising GP practices and other community health services).
The Crown was supposed to work with Māori to change that, but had not, they said.
Abolishing the authority would be inconsistent with the Treaty principles of tino rangatiratanga, partnership and equity, the claim said.
Prime Minister Christoper Luxon said the government was considering the claim and would respond in due course.
He said the Māori Health Authority was suboptimal in its first year and added bureaucracy would not help improve Māori health outcomes.
"We want to see Māori, [and] we want to see non-Māori doing well in this country. We are determined to work with iwi and Māori organisations to achieve outcomes," he said
Lady Tureiti said Te Aka Whai Ora was being labelled as race-based but it was trying to achieve what the "one system for all" had failed to do.
"By Māori for Māori solutions to addressing these issues for ourselves is what is needed. It's important that the government upholds the Treaty partnership and its obligations or otherwise, this is another breach of our rights to participate in our own health and wellbeing."
The plan to end it was a breach of the Treaty, she said.
It was one of the recommendations made by the Waitangi Tribunal to try to give Māori mana motuhake.
"Given the number of premature deaths from preventative diseases, this was an empowered solution to address the inequities of the health system and adverse outcomes for Māori in Aotearoa."
Earlier this week, Ngāi Te Rangi lodged an urgent application with the Tribunal over government policies targeting te reo Māori.
The Tauranga Moana Iwi says the government has breached Article 2 of Te Tiriti o Waitangi.