New Zealand’s parliament was briefly suspended on Thursday after Maori members staged a haka to disrupt the vote on a contentious bill that would reinterpret a 184-year-old treaty between the British and Indigenous Maori.

Rawhiti Maipi-Clarke of Te Pāti Māori stood and began a rhythmic Māori chant of challenge, which swelled to a roar as opposition lawmakers and spectators in the public gallery joined in.

The Treaty Principles Bill seeks to revise New Zealand’s foundational agreement with Maori people and is hugely unpopular, with even the prime minister deriding it.