Te Kohanga Reo National Trust Board has opened an urgent Waitangi Tribunal hearing by calling for a law change taking control of the Maori preschools away from the Ministry of Education.
Kohanga were established in 1982 and there are about 480 centres in the country.
The kohanga movement says they are not early-childhood centres, yet are being forced to adopt a mainstream model in line with those centres.
It says the number of centres has halved during the past 15 years of being managed by the ministry.
Trust deputy Toni Waho says a law change giving Maori control is needed for the sake of both the language and the growth of kohanga centres.
Mr Waho says they get about $50 million in funding each year, which is considerably less than early-childhood centres get.
The Waitangi Tribunal hearings are set down for a fortnight.