ACT targets judicial use of tikanga and Treaty clauses in new constitutional policy

The ACT Party has released a policy package targeting what it calls "activist judges" and Parliament's tendency to insert vague Treaty of Waitangi clauses into legislation, proposing constitutional and statutory amendments to assert parliamentary sovereignty and limit the role of tikanga in court decisions. (RNZ)

Party leader David Seymour framed the policy as a question of legal equality. "Ensuring New Zealanders can move forward under one law for all with one future together," he said of the policy's purpose. The announcement follows a pledge Seymour made on 16 December 2025 to reignite the Treaty principles debate in 2026, saying he would never move on from his vision for it. (Te Ao News) Seymour had previously justified the party's Treaty Principles Bill by arguing that "activist judges and bureaucrats" had "twisted" the Treaty of Waitangi principles. (Law News)

The centrepiece of the policy is a proposal to add three principles to the Constitution Act: that Parliament is sovereign, that the rule of law is fundamental, and that all New Zealanders are equal before the law.

A key element is restraining courts from considering Māori tikanga (custom) in their decisions. Seymour said recent Supreme Court decisions had pushed the line further than Parliament ever legislated. He pointed to Parliament pushing back in the Smith v Fonterra and Marine and Coastal Area cases, but not in the Ellis case, where the Supreme Court expanded the use of tikanga in the law. ACT proposed making clear that tikanga cannot be used to influence court decisions except where Parliament has expressly allowed for it.

The policy also targets statutory interpretation. ACT proposed amending the Legislation Act 2019 to ensure statutes are enacted in the context of the time they were passed. Judges could resolve ambiguity but not override statutory language.

On the legislative front, ACT proposed stopping governments from writing vague treaty clauses into law that create uncertainty and leave courts and officials to interpret them. Under the policy, any bill referring to the Treaty of Waitangi would require Cabinet to agree which interests were engaged, who they apply to, and what obligations they create.

Looking at what this means in practice, the package touches several live constitutional fault lines simultaneously. The proposal to codify parliamentary sovereignty and equality before the law in the Constitution Act would, if enacted, give those principles statutory grounding they do not currently have in a single instrument. The Constitution Act 1986 is not entrenched; it can be amended by ordinary legislation. Whether a future Parliament would treat these additions as binding in practice, or merely declaratory, is a question the policy does not address.

The tikanga restriction is the element most likely to draw sustained response from the legal profession. The Supreme Court's decision in Ellis v R, which recognised tikanga as part of the common law of New Zealand where relevant, was widely regarded within the bench and legal academy as a careful, incremental step. Restricting its application to only those areas where Parliament has expressly provided would shift interpretive authority over tikanga's legal role from the judiciary to the Legislature. That is a structural change to the separation of powers, not merely a policy disagreement about outcomes.

The Legislation Act amendment proposal also bears scrutiny. The current Act already directs courts to interpret legislation in accordance with its text and purpose. What ACT is proposing appears to narrow interpretive discretion further by anchoring meaning to the context of enactment, which would constrain purposive interpretations that rely on evolving social context.

The Treaty clause mechanism requiring Cabinet sign-off on scope, application and obligations would, if adopted, impose a new procedural discipline on the executive. Legislation containing Treaty references has historically varied widely in specificity, from broad statements of principle to detailed procedural requirements. The proposal would standardise that at the front end of the policy process.

For gallery observers, the policy reprising the Treaty principles territory that proved politically contentious for ACT during the previous parliamentary term is notable. Seymour's December 2025 commitment to reignite the debate was unequivocal, and this package delivers on it with a more developed statutory architecture than the earlier Treaty Principles Bill. Whether National would entertain any of these proposals in a coalition negotiation after the 2026 election is the political question that now sits alongside the constitutional ones.