Waikato-Tainui is taking the Government to the High Court over its policy to roll back te reo Māori in the public sector.
Iwi members have filed legal action in Wellington against the move, which they believe breaches their 1995 Raupatu treaty settlement outlining the protection of te reo Māori.
In a statement, Treaty Negotiations Minister Paul Goldsmith said the Government takes treaty matters seriously and will honour existing treaty settlements, and want to resolve outstanding settlements.
Tauranga-based iwi Ngai Te Rangi has also made a claim to the Waitangi Tribunal, accusing the government of attacking Māori culture and language Iwi members travelled with Tainui to Wellington to support their court action.
Waikato-Tainui kaikorero Tukoroirangi Morgan spoke with Charlotte Cook.