About 70 kohanga reo supporters from around the country have been putting their case to the Waitangi Tribunal for an urgent hearing.
The movement is worried about its survival and began two days of submissions to the tribunal in Wellington on Wednesday.
The Kohanga Reo Trust Board filed the claim under urgency, because it believes a government report on early childhood poses a threat to its kaupapa Maori teaching model.
It says rules governing mainstream pre-school centres should not be imposed on kohanga.
The board must now show why the Waitangi Tribunal should hear its claim under urgency.
The Crown's opposing the request saying the matter's significant but doesn't warrant immediate attention.