By Roger Partridge

Has the Supreme Court once again stepped outside its lane? A recent ruling about who controls our coastlines suggests our highest court is trying to reshape laws made by Parliament, rather than just apply them.

Even more concerning is the Court’s extraordinary haste in delivering its judgment, just as Parliament prepared to debate changes to the law.

This judicial activism should concern every New Zealander. The recent decision concerned customary title over harbours and coastline in the eastern Bay of Plenty. Known as the Edwards case, it involved iwi claims under the Marine and Coastal Areas Act. The Act was passed in 2011 by the National-led government with the support of the Māori Party.

At the heart of this story is a simple question: When do iwi have traditional rights over coastal areas? Parliament answered this in the 2011 Act with a two-step test. First, iwi must show they have a traditional connection to the area through tikanga (Māori customary practices). Second, they must prove exclusive use and occupation of that area since 1840 without substantial interruption. Parliament drafted this second step as a separate assessment without explicit reference to tikanga.

To understand Parliament’s approach, consider how one might establish a historical claim to land: first proving a legitimate ancestral connection, then separately demonstrating continuous exclusive occupation.

When Parliament’s careful two-step test arrived in the court system, the judges quickly dismantled it.

The High Court departed from Parliament’s design by reading tikanga considerations into the second step. They decided that “exclusive use” could be shared between different groups when viewed through a tikanga lens – a contradictory outcome that Parliament’s precise drafting would have prevented.

The Court of Appeal went even further. It ruled that exclusive use could only be “substantially interrupted” by activities that were legally authorised. This meant that even if other groups had been using the coastal area extensively for generations, it would not count as an interruption unless they had statutory permission. This interpretation significantly lowered the threshold for establishing customary title.

When the case reached the Supreme Court, many expected it to correct this problem. And, on an initial reading, it did so. The Supreme Court rejected the Court of Appeal’s view that only statutory authorisations could constitute “substantial interruption”.

However, the Court’s approach still fundamentally misinterpreted the Act’s design. The Court insisted that tikanga considerations must still be read into the second step, despite Parliament omitting them. As a result, the Court’s decision preserves the concept of shared exclusivity. This leaves the core problem with the lower courts’ approach intact.

What makes the Supreme Court’s judgment more troubling, however, is its timing and haste. The Court took just 17 days to issue its judgment after hearing complex arguments from 19 parties.

The timing was striking. The Court delivered its decision on the eve of Parliament’s scheduled debate by taking the unusual step of splitting its judgment in two. Rather than resolve the appeals between the parties before it, the Court rushed out its interpretation of the customary title test, leaving its decision on how the law should apply to the facts for later.

This unusual approach suggests a Court more focused on influencing Parliament’s debate than on resolving the case before it. It suggests a court that sees itself more as a political player, than an impartial arbiter of disputes.

The Supreme Court’s approach in Edwards fits a broader pattern of judicial overreach discussed in my recent report, “Who Makes the Law? Reining in the Supreme Court.” The Legislation Act requires courts to give effect to Parliament’s intended meaning. Instead, our highest court is too often stretching – or even ignoring – Parliament’s language to achieve outcomes it prefers.

Last year, senior barrister Jack Hodder KC highlighted how the Court has turned statutory interpretation into a “constitutional battlefield.” Hodder’s influential delivered his influential critique at a conference marking the Court’s 20th anniversary. He warned of “unprecedentedly sharp political debate” about the Supreme Court’s role.

The coalition agreement between National and New Zealand First provides for amendments to the Marine and Coastal Areas Act to “make clear Parliament’s original intent.” Following the Supreme Court’s Edwards decision, the government deferred its proposed amendments pending Crown Law advice.

But a legislative response is both necessary and appropriate. As the Senior Courts Act states, Parliament is sovereign in our constitutional hierarchy. Courts gain their legitimacy from being impartial. When they insert themselves into policy debates or try to influence legislation, they risk undermining public confidence. They also undermine the rule of law by creating legal uncertainty.

The Edwards case demonstrates exactly these risks. A rushed judgment timed to sway Parliament. An unusual split decision process. And policy-making disguised as interpretation.

While due process matters, Parliament must not shy away from correcting the Court’s misinterpretation. But systematic reform is also needed. This should include defining the rule of law more precisely, tightening interpretation rules and emphasising judicial restraint in the appointment of judges.

The message to our highest court should be clear: focus on resolving disputes by applying the law as written. Leave lawmaking to our elected representatives.

Originally published on The New Zealand Initiative.