Te Taura Whiri i te Reo Maori says a recent High Court decision is a big loss for the Maori language and sets a precedent that may lead to the erosion of its place in courts.
The Maori Language Commission was part of a judicial review of a Waitangi Tribunal judge's decision to require a lawyer to question witnesses in English, not Maori.
The High Court ruling upheld that people have a right to speak te reo in legal proceedings, but wouldn't overrule the decision, saying tribunals can determine how time is used.
Commission chair Erima Henare says in other words, a choice must be made between exercising the right to speak te reo Maori and having time to ask more questions.
Mr Henare says that creates a precedent where counsel and witnesses may be discouraged from using te reo in courts on the grounds of convenience or cost.