ACT Party leader David Seymour's acknowledgement that Ngāi Tahu have rangatiratanga over most of the South Island shows the inconsistency of his argument, says a legal expert.
Another says the "apparent concession" shows how "unworkable" his Treaty Principles Bill is.
Seymour's acknowledgement came on TVNZ's Q+A show, where host Jack Tame asked, under his proposed principles, whether Seymour accepted that Ngāi Tahu had "full sovereignty over 90 percent of the South Island".
Seymour pointed to his Bill's commitment not to override any Treaty settlements, and said it would depend on the interpretation through the courts.
"We've said that we're going to accept or we're not going to mess with Treaty settlements, so you're required to follow those.
"Funnily enough, I think that's why we have courts, however, that would be a plain reading of what it says."
Dr Carwyn Jones - senior lecturer in the Faculty of Law at Victoria University of Wellington - said his acknowledgement raises "a whole lot of questions".
"They're comfortable to recognise tino rangatiratanga in that agreement, why not comfortable to recognise tino rangatiratanga as guaranteed in Te Tiriti to all the other iwi and hapū?"
Jones said Seymour talking about the courts being left to determine how the Treaty relationship played out or was recognised was inconsistent with his refusal to accept the courts judgements on the Treaty Principles.
"And yet, here he's saying, well, actually, of course, the way in which you would determine how Tino Rangatiratanga gets recognised through the Ngāi Tahu Claims Settlement Act is by discussions and working through in the courts where there is dispute and those kinds of things."
Jones said he seemed "comfortable to use that process in that context".
"A lot of the discussion we've seen from David Seymour around this bill is we have seen things which are a little bit contradictory or hypocritical, and ... does indicate to me that he's not actually interested in promoting a good faith conversation about Te Tiriti, but he's actually trying to push a particular political agenda for his own political gain."
Jones pointed to another segment of the interview where Seymour was pushed on what he thought Te Tiriti meant when signed.
Tame said Seymour's opponents would argue that "nowhere in the Treaty does it actually guarantee everyone that level of Tino rangatiratanga, that it specifically includes a carve out for iwi and hapu".
"It said it would give tino rangatiratanga to all the people of Niu Tireni, all the people in New Zealand," responded Seymour, acknowledging that most people would say "clearly that meant just the chiefs that were there in 1840 right?".
Seymour went on to say he thinks it should mean "all the people of New Zealand," and eventually said "I don't know, nobody knows for sure" what it did mean.
Jones said it intrigued him that Seymour initially would not respond to what he thinks it did say, but what he thought it should say. Jones said that indicated the principles proposed in the Bill "don't actually reflect Te Tiriti" and that "David Seymour knows that they don't reflect Te Tiriti".
"So that's different to what he's been going around telling everybody. And it also does indicate that actually he does want to change the meaning of Te Tiriti."
In a statement to RNZ, Seymour said the legal experts' argument "doesn't stack up".
"Parliament can disagree with the principles proposed by the courts and legislate to change them while protecting the rights of everyone, including Māori, and upholding Treaty settlements."
He said that was exactly what his Treaty Principles Bill did.
"The problem these legal experts have is that their interpretation, which says there are two types of people in New Zealand who each have different political and legal rights, is inconsistent with equal rights and liberal democracy."
Another expert - KC Karen Feint - said his "apparent concession" that Ngai Tahu have the right of tino rangatiratanga "because it was provided for in their historical Treaty claims settlement" showed how unworkable his Treaty Principles Bill was.
Feint was one of a number of lawyers who called for the Bill to be abandoned.
"Historical Treaty claims' settlements resolve historical claims, but it is wrong in principle to conceive of the Treaty partnership as being frozen at a moment in time or only backwards looking."
She said the Article Two guarantee of tino rangatiratanga "applies to all iwi and hapū, not just some, and it frames the constitutional relationship between the Crown and Māori".
Pressed for confirmation in the Q+A interview that Ngai Tahu have tino rangatiratanga over 90 percent of the South Island, Seymour responded "that's what a previous government signed up to in a treaty settlement," and "unfortunately, that's the settlement that's in place".
Seymour said he was not sure he would have put it that way, but "parliament signed off" and he had been very clear "in this legislation that we're not going to interrupt or in any way mess with Treaty settlements".
When asked what the implications of that finding was, Seymour said it was "many of the problems that you'd expect to come out of the current principles of the Treaty".
He said the implications will depend on different case law and what question was being asked at a particular time.
"What I can say is it's inconsistent with the idea that all people who live in the South Island, many of them, most of them, it's the only home they have. And you have through that treaty settlement, as you read it, a set of rights that are inconsistent with liberal democracy and equality before the law, that's a shame, but that's where they're up to."
Seymour added in the statement to RNZ he believed the Treaty promised what it said: "nga tikanga katoa rite tahi - the same rights and duties for all New Zealanders."
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