Maōri continue to be marginalised in the education system, Kura Kaupapa says, ahead of its presentation of an urgent inquiry to the Waitangi Tribunal.
The tribunal will hear the inquiry from the body which oversees Kura Kaupapa Māori later this month.
The claim from Te Rūnanga Nui o Ngā Kaupapa Māori o Aotearoa concerns Crown practices, which it argues continue to marginalise Māori in the education system.
It is 38 years since the first full-immersion kura kaupapa opened.
Since then, there has been a tug of war between the Crown and Te Rūnanga Nui over who has authority to decide how Māori are taught and learn.
The rūnanga wants to establish a parallel system of funding for matauranga Māori learning.
Te Rūnanga Nui co-chairperson Rawiri Wright claimed the Crown had not adequately demonstrated the ability to cater for Māori, Pasifika and special needs students.
"[In] 207 years they still haven't got it right, the Crown," Wright said.
"[In] 38 years we are doing something right, let us manage our own education system for the betterment of not only Māori tamariki, but any tamariki who speak Māori, who want to participate in this education option."
Wright, who is tumuaki of a kura in Wellington, said achievement results showed why there should be devolution.
"We have demonstrated for 10 to 15 years how successful our students can be. We're not just talking about scholastically, no, we are talking about producing people of good character."
Te Rūnanga chief executive Hohepa Campbell said the report was highly critical of the Ministry of Education.
"That report by the Tomorrow's Schools Taskforce was very clear to the Crown in that it recommended that the Ministry is incapable of supporting Kura Kaupapa Māori in order for them to flourish."
The main claimant was Dr Cathy Dewes, one of the architects of Kura Kaupapa Māori and Te Aho Matua - the blueprint for how kura kaupapa are managed and organised.
She has said years of underfunding meant there were a range of issues affecting kura, from a lack of resources in te reo to old school buildings.
And government policies had made it much more difficult to establish a kura; 43 were established between 1985 and 2000, but only 19 had been set up in the 20 years up to 2021.
Wright said too often teachers and whānau had to pick up that slack by themselves.
"There's a national shortage of teachers and that is particularly pronounced within kura kaupapa Māori Aho Matua, where kaiako, in addition to having a teaching qualification, they need to be fluent speakers of Māori, they need to be able to deliver all manner of subjects in Māori to the highest level."
Three hearings over the next two months are set down so far across the country.
Associate education minister Kelvin Davis said Kura Kaupapa Māori had a right to have their grievances heard by the Waitangi Tribunal.
But he said because it was an active inquiry it would be inappropriate for him to comment further.