Does New Zealand law need a constitutional change?

Unjust, illegitimate and illegal is how a legal scholar describes New Zealand's constitution in her new book, which calls for fundamental change to constitutional law.

Professor Claire Charters told RNZ's Saturday Morning Aotearoa was unique in that it didn't have a single written constitutional document.

"Very unusual, one of only a couple in the world... our constitution is made up of statutes and conventions and law made by the courts, so that might include statutes like the Human Rights Act."

Another unusual point in the country's legal makeup is that courts cannot overturn legislation that is inconsistent with rights or what could be understood as fundamental constitutional values.

Charters discusses what this means for the country from a Māori perspective, something she said was lacking and necessary for everyone

"I do think that if you're in a nation that doesn't respect Māori rights or the rights of refugees or other groups... I think that's a problem for everyone.

"To live in a state where rights of any group are subject to being overturned is a problem for everyone."

She argues New Zealand has some of the weakest levels of legal protection globally when it comes to indigenous sovereignty.

"In Canada, in the US, for example, treaties with indigenous peoples have higher law status. They trump or take precedence over legislation that is inconsistent.

"So pretty powerful. I mean, imagine if Te Tiriti o Waitangi had that higher law status, and every law in Aotearoa had to comply with Te Tiriti o Waitangi."

Charters said New Zealand was in breach of indigenous rights in different ways.

She referenced the overturning of activist Mike Smith's case against Fonterra, Z Energy and other major emitters as one example.

"The Treaty Principles Bill, which is clearly a rights breach on some level, to, gosh, the Electoral Act amendments, going back to that, were just so cynical, in my view,

"The government knew, that that would have an incredibly disproportionate impact on Māori voters, and Pasifika voters, and youth, and Asian voters.

"Our institutions like the Waitangi Tribunal, which carry enormous mana and do an incredible job... its recommendations are not binding."

She said it was an "orthodox understanding" in legal circles that Māori did not cede sovereignty in Te Tiriti o Waitangi even if it was not always understood in political, societal circles.

"It astounds me how many people have not sat down and read that very short document, or translations of the Te Reo Māori version.

"We need to have Māori reflected in our constitution. If it's just imposed upon us, and we can't see ourselves in this constitution, that is incredibly divisive."

She proposed several different ways of approaching this including jurisdictional changes, the idea of a Māori senate or having greater rights protection for everyone.

"I think we need to understand the importance of constitutional transformation that will enable us to live up to our human rights obligations under international law, our indigenous people's rights obligations.