How do the Treaty of Waitangi and tikanga Māori affect statutory decision-makers?

By Alex Young

30 May 2023

In light of two recent decisions, the first by the Supreme Court in Trans-Tasman Resources Ltd v Taranaki-Whanganui Conservation Board (which considered whether discretionary decision-makers are obliged to comply with the principles of the Treaty of Waitangi (Te Tiriti) when making decisions), and the second by the High Court,(1) statutory decision-makers may need to give greater consideration to the applicable principles of Te Tiriti and tikanga Māori.



Treaty of Waitangi

Te Tiriti, signed in 1840, is regarded as New Zealand's founding instrument.(2) Sir Robin Cooke described Te Tiriti as "simply the most important document in New Zealand's history".(3)

It is a succinct written document, comprising a preamble and three articles.(4) With clear differences between the English and Māori texts,(5) the Waitangi Tribunal has applied the contra proferentum rule to hold that the authoritative text is the Māori version.(6) Although historically it was not always accorded such standing,(7) Te Tiriti has been held to be cognisable at law.(8) Legislative references to Te Tiriti have proliferated since the mid-1970s(9) and, consequently, this article primarily addresses decisions made under enactments containing an express treaty clause.

The Court of Appeal's landmark decision in New Zealand Māori Council v Attorney-General, which concerned the application of a treaty clause,(10) addressed:

  • the spirit of Te Tiriti;
  • the differences between the English and Māori texts;
  • past breaches of Te Tiriti; and
  • the appropriate interpretive approach to the principles of Te Tiriti.

It held that "partnership" was the key concept which created reciprocal responsibilities "analogous to fiduciary duties",(11) requiring the treaty parties to act towards each other with "utmost good faith".(12) The Court of Appeal held that treaty rights were not enforceable by action in the absence of statutory incorporation.(13) However, as regards statutory interpretation, Cooke P held that the courts "will not ascribe to Parliament an intention to permit conduct inconsistent with the principles of the Treaty".(14)


Tikanga Māori

Tikanga Māori is a body of Māori customs and practices.(15) Its basis is in the system of custom brought to New Zealand by the Hawaikian explorer, Kupe.(16) Tikanga is an old legal system, oriented around notions of kinship, later adapted to new circumstances of place. It is a values-based system that is internally both coherent and flexible, and suited to small communities where making peace had primacy, alongside keeping to principle.(17)

Tikanga is "law designed for small, kin-based village communities . . . concerned with peace and consensus", as well as certainty.(18) The Law Commission described the articulation of its core values in a 2001 study Māori Custom and Values in New Zealand Law as a fraught exercise,(19) but they can be best understood as:(20)

  • whanaungatanga, or the source of the rights and obligations of kinship;
  • mana, or the source of rights and obligations of leadership;
  • tapu, as both a social control on behaviour and evidence of the indivisibility of the divine and profane;
  • utu, or the obligation to give and the right (and sometimes obligation) to receive constant reciprocity; and
  • kaitiakitanga, or the obligation to care for one's own.

Trans-Tasman Resources

Trans-Tasman Resources Ltd v Taranaki-Whanganui Conservation Board(21) concerned an appeal against the Environmental Protection Authority's (EPA's) approach to granting consent under the Exclusive Economic Zone (EEZ) and Continental Shelf (Environment Effects) Act 2012 to extract and process iron ore from the South Taranaki Bight. The Supreme Court held that the EPA's approach was flawed and directed that it reconsider its decision.(22)

The decision has potential consequences for a range of areas of law. The Court expressly ruled on:

  • the application of Te Tiriti to the EEZ Act's treaty clause (section 12);
  • the implications of the Marine and Coastal Area (Takutai Moana) Act 2011; and
  • the place of tikanga as law in New Zealand.

The decision contains clear and definitive statements that reflect the growing acknowledgement of the place of tikanga in New Zealand's legal system.(23)

Section 12(c) of the EEZ Act provides that in order to recognise and respect the Crown's responsibility to give effect to the principles of Te Tiriti for the purposes of the Act, section 59 requires the minister and a marine consent authority "to take into account the effects of activities on existing interests". For this purpose, section 59(2) provides a list of matters that a marine consent authority must take into account, including "any other applicable law".(24) The Supreme Court took an expansive approach and held that "any other applicable law" in the context of section 59(2)(l) included tikanga Māori.(25) It stated that "the courts will not easily read statutory language as excluding consideration of Treaty principles if a statute is silent on the question"(26) and "an intention to constrain the ability of statutory decisionmakers to respect Treaty principles should not be ascribed to Parliament unless the intention is made quite clear",(27) especially "given the constitutional significance of the Treaty to the modern New Zealand state".(28)

Moreover, the section 12(c) Te Tiriti clause provided "strong direction" for the EPA's decision making committee to "take into account the effects of the activity on the existing interests in a manner that recognises and respects the Crown's obligation to give effect to the principles of the Treaty".(29) The application of the principles of Te Tiriti meant "the decision-maker would look at the tikanga itself and consider what it might say about the rights or interests of customary "owners" or of the resources itself". For example, the decisionmaker considering "the proposed activity in terms of tikanga may indicate that material harm extends beyond the physical effects of a discharge, or that pollution can be spiritual as well as physical".(30) This decision is significant for its recognition of tikanga's role, and its impact can also be seen in more recent decisions.

Students for Climate Solutions v the Minister of Energy and Natural Resources

The decision in Students for Climate Solutions(31) addressed a challenge to decisions to grant two petroleum exploration permits.(32) The applicant argued on various grounds that the decision-maker had failed to consider, substantively, the climate change implications of the decisions. One ground advanced was the failure to have proper regard of the principles of Te Tiriti.(33)

After noting Te Tiriti section (section 4) in the Crown Minerals Act 1991, the High Court accepted that the ultimate effect of the Trans-Tasman decision might be that discretionary decision-makers are obliged to comply with the principles of Te Tiriti, absent express provision.(34) Noting that such an approach would recognise that Te Tiriti principles have the significance described in earlier cases,(35) the Court accepted that the principles of Te Tiriti were part of the principle of legality:(36)

Parliament is presumed not to empower statutory decision-makers to make decisions that are inconsistent with the rights in the New Zealand Bill of Rights Act 1990, other accepted fundamental common law principles, or New Zealand's international obligations. These requirements are collectively referred to as the principle of legality. Given the Treaty's constitutional significance, a similar presumption should arise in relation to its principles. They are also part of the principle of legality in New Zealand. (Emphasis added and footnotes omitted.)

The decision observed the importance of addressing the principles of Te Tiriti where legislation contains a treaty clause.(37) However, the particular formulation of the treaty clause was not critical; the central principle was that, when Parliament requires the decisionmaker to take into account the principles of Te Tiriti, the "natural inference" is that the court must ensure that the principles are not infringed.(38) What matters is the legislative indication that the principles need to be addressed, with the natural inference that they must be honoured unless Parliament provides otherwise.(39)

The decision indicated that, following Trans-Tasman, the principles of Te Tiriti formed a key component of the principle of legality.(40) As a result, even when there is no express treaty provision in the relevant legislation, discretionary decision-makers are obliged to comply with the principles of Te Tiriti,(41) such that "if the principles of the Treaty engage climate change issues then they become relevant to the decision".(42)

Importantly, however, taking into account the principles of Te Tiriti would not mandate a particular outcome, as consideration of the treaty principles would involve balancing a number of competing values, including both rangatiratanga (control retained by the Māori signatories) and kāwanatanga (governorship conferred on the Crown).(43) The decision-maker was held to have assessed Te Tiriti principles satisfactorily and acted in accordance with the relevant power and purpose of the Crown Minerals Act when granting the exploration permits.

Further judicial recognition of Te Tiriti and tikanga principles

More generally, the courts have shown an increasing awareness of and willingness to engage with tikanga- and treaty- related arguments. Similarly, parties to litigation appear to be increasingly viewing tikanga and treaty arguments as a viable basis for a claim or defence. The following cases are three recent examples of this trend.

Ellis v R

The Supreme Court decision in Ellis,(44) addressed whether a criminal appeal should proceed following the death of the appellant. The decision included discussion of the role of tikanga in the common law following a judicial request for submissions on whether the principles of tikanga could and should influence the decision to hear an appeal despite the appellant's death.

The majority held that tikanga:

  • was the "first law" of New Zealand;(45)
  • has been, and will continue to be, recognised in the development of the common law of New Zealand;
  • is firmly embedded in statutes and regulations; and
  • may, as a result, influence the exercise of discretion as a relevant consideration.(46)

The Supreme Court expressly urged caution, stressing that it "must not exceed [its] function when engaging with tikanga", and that "[c]are must be taken not to impair the operation of tikanga as a system of law and custom in its own right".(47)

Smith v Fonterra Co-Operative Group Ltd

This decision involved an appeal, where the applicant was Māori elder Mr Smith, of the High Court's strike-out decision on a claim for judicial review brought against seven large New Zealand companies. The appeal alleged that greenhouse gases emitted as a result of Fonterra Co-Operative Group Ltd's business activities contributed to adverse effects of climate change.(48) Smith's claim focused around three causes of action which did not originally have reference to tikanga. In the Court of Appeal, Smith amended his pleading to include reference to tikanga. This was not pleaded as a separate cause of action but was pleaded as a "principle and value" to "infuse the court's consideration of the issues".(49) On the tikanga point, the Court of Appeal held that controlling climate change by regulatory means (rather than by judicial review) would be consistent with the principle of kaitakitanga (guardianship).(50)

The Court of Appeal upheld the High Court's decision to strike out the first two causes of action and allowed the cross-appeal, also striking out the third cause of action. The Court held that there were strong policy reasons against imposing private law duties on greenhouse gas emitters and that matters of this complexity were best dealt with legislatively. Leave to appeal to the Supreme Court was granted, affording the Supreme Court the opportunity to consider how the common law might be altered to account for tikanga, or be altered as to incorporate tikanga into the common law directly.

Doney v Adlam

The High Court's decision in Doney v Adlam(51) served to re-emphasise that the application of tikanga to any particular case is a highly factually specific exercise. It also demonstrated that parties should not expect to be able to "cherry pick" principles of tikanga that are favourable to their argument. The case related to a dispute that had its genesis in issues arising from repayment of a judgment debt to a Māori land trust. Tikanga arguments were deployed by the respondent seeking to prevent enforcement of the judgment debt under the High Court Rules 2016. The Court accepted that tikanga was relevant but found that, contrary to the respondent's position, the relevant tikanga principles were, in fact, consistent with enforcement.


The decisions outlined above show the development of recognition of tikanga by the courts on a case-by-case basis. It now seems established that tikanga Māori and the treaty principles are relevant to the principle of legality in public decision-making. Absent clear words of exclusion, the potential application of tikanga Māori and the treaty principles should be assumed as a matter of principle. However, whether tikanga Māori and the treaty principles are applicable to a matter, in the sense of changing outcomes, is highly dependent on establishing their relevance to the matter at hand. Both tikanga and treaty principles involve the balancing of competing considerations. In addition, both tikanga and the development of treaty principles are constantly evolving and, in the case of the former, are subject to local variation. No comprehensive statement or checklist applicable to all cases exists.


(1) Students for Climate Solutions Inc v The Minister of Energy Resources [2022] NZHC 2116.
(2) Phillip A Joseph Joseph on Constitutional and Administrative Law (fifth edition, Thomson Reuters, Wellington, 2021) at [4. 1].
(3) Sir Robin Cooke "Introduction" (1990) 14 NZULR 1 at 1.
(4) Both its English and Māori text can be read in the Treaty of Waitangi Act 1975 at Schedule 1.
(5) New Zealand Maori Council v Attorney General [1987] 1 NZLR 641 (HC and CA) [Lands Case] at 671-672 per Richardson J; and
Latimer v Commissioner of Inland Revenue [2004] 3 NZLR 157 (PC) at [2].
(6) See for example Report of the Waitangi Tribunal on the Manukau Claim (Wai-8, 1985) at 65, citing Jones v Meehan (1899) 175 US 1
(treaties to be construed "in the sense which they would naturally be understood by Indians").
(7) In Wi Parata v Bishop of Wellington (1877) 3 NZ Jur (NS) 72 (SC) at 78 Prendergast CJ expressed the view that Te Tiriti, insofar as it
was purported to cede sovereignty, was a "simple nullity".
(8) Huakina Development Trust v Waikato Valley Authority [1987] 2 NZLR 188 at 206.
(9) Joseph, above No. 2, at [4. 9. 4]. See, as an early example of importing tikanga into a particular category of law, Resource
Management Act 1996, sections 7 and 8.
(10) Lands Case, above No. 5.
(11) At 664 per Cooke P.
(12) At 664 per Cooke P and 693 per Somers J.
(13) At 655 per Cooke P. See also at 691 per Somers J, affirming that sovereignty in New Zealand resides in Parliament.
(14) At 655-656 per Cooke P.
(15) Dealt with in detail by the Waitangi Tribunal in Waitangi Tribunal Ko Aotearoa Tinei: A Report into Claims Concerning New Zealand
Law and Policy Affecting Māori Culture and Identity (Wai 262, 2011).
(16) For more detail, refer to Joseph Williams "Lex Aotearoa: An Heroic Attempt to Map the Māori Dimension in Modern New Zealand
Law" (2013) 21 Wai L Rev 1 at 2, citing Waitangi Tribunal, above No. 15, at 5.
(17) At 5.
(18) Williams, above No. 15, at 3.
(19) New Zealand Law Commission Māori Custom and Values in New Zealand Law (NZLC SP9, 2001) at [124] – [166].
(20) Williams, above No. 16, at 3.
(21) Trans-Tasman Resources Ltd v Taranaki-Whanganui Conservation Board [2021] NZSC 127, [2021] 1 NZLR 801. Matthew Smith "How
tikanga and Te Tiriti are shaping our administrative law" (paper presented at Administrative Law Intensive, Wellington, November, 2022)
provides a helpful explication of tikanga principles and the Trans-Tasman decision's implications.
(22) At [12].
(23) In this sense it adds to a growing line of jurisprudence including:

  • Takamore v Clarke [2012] NZSC 116, [2013] 2 NZLR 733;
  • Ngāti Whātua Ōrākei Trust v Attorney-General [2018] NZSC 84, [2019] 1 NZLR 116;
  • Ellis v R [2020] NZSC 89; and
  • Ellis v R [2022] NZSC 114.

(24) For a helpful outline of how the issues in the case arose, see: Elizabeth Macpherson et al "Trans-Tasman Resources v Taranaki
Whanganui Conservation Board [2021] NZSC 127: A New "High-Water Mark" for Seabed Mining" (2021) 25 NZJEL at 227.
(25) Trans-Tasman Resources Ltd, above No. 21,at [169].
(26) Trans-Tasman Resources Ltd, above No. 21, at [151], also [237], [296] and [332].
(27) Trans-Tasman Resources Ltd, above No. 21, at [151], also [137], [296] and [332].
(28) At [151] per Young and France JJ
(29) Quoting from Young and France JJ at [149], but see also [237] per Glazebrook J, at [296] per Williams J and at [332] per Winkelmann
(30) At [172] per William Young and Ellen France JJ.
(31) Students for Climate Solutions, above No. 1.
(32) At [1].
(33) At [2(c)].
(34) At [90] and [91], referring to Trans-Tasman at [151], [137], [296] and [332].
(35) At [91], citing: New Zealand Māori Council v Attorney-General [1987] 1 NZLR 641 (CA) at 656 and Huakina Development Trust v Waikato Valley Authority & Bowater [1987] 2 NZLR 188 (HC) at 210.
(36) At [91].
(37) At [92].
(38) At [92].
(39) At [92].
(40) See at [99]: "the principles of the treaty are made relevant by s 4, and also by the principle of legality".
(41) At [90] and [91] referring to Trans-Tasman at [151], [137], [296] and [332].
(42) At [99] citing: Greenpeace New Zealand Inc v The Minister of Energy and Resources [2012] NZHC 1422 at [111] and [116].
(43) At [100] and [111].
(44) Ellis v R [2022] NZSC 114.
(45) At [22].
(46) At [19].
(47) At [22]. See also at [120] per Glazebrook J.
(48) Smith v Fonterra Co-operative Group Ltd [2021] NZCA 552.
(49) At [8].
(50) At [34].
(51) Doney v Adlam [2023] NZHC 363.