Chief Justice Sian Elias is challenging the long-established convention of courts steering clear of decisions which relate to legislation before Parliament.
She made her views knows in a recent Supreme Court judgment and is effectively saying the principle of non-interference by the courts in parliamentary proceedings has been taken too far.
The criticism is as much to other judges in lower courts and she said some of the recent restatements of the principles of non-interference "are unacceptably broad".
The case in question involved Ngati Whatua challenging the Crown's intended transfer of specific Auckland properties involving two other Treaty of Waitangi settlements, which are intended to be activated under settlement legislation.
The High Court and Court of Appeal dismissed Ngati Whatua's claim, saying it was effectively a challenge to legislation because the outcome of the transfer could be secured only through parliamentary legislation.
But the Supreme Court overturned them and said Ngati Whatua could reargue its case if it was put as a claim about existing rights.
Elias in a self-penned part of the Supreme Court judgment said it had been suggested it was inappropriate to determine existing rights when the Government had indicated its intention to ask Parliament to change the law, because to do so would encroach upon the legislative function.
"This creep in restriction of established constitutional obligations of courts not to interfere in proceedings of Parliament is put on the basis that it observes appropriate 'comity' between the courts and the legislature.
"I consider it to be an unwarranted extension of proper principle," Elias said.
No determination of existing rights in itself constituted an interference with the proceedings in Parliament, she said.
"Indeed in some cases it might provide information that Parliament might want to consider."
She said the constitutional functions of the courts were not enlarged by her approach.
Rights at issue in the courts could always be changed by legislation. That prospect did not deflect the courts from carrying out their responsibilities.
"Nor are they deflected by statements of Government policy that legislative change will be sought. Such statements cannot mark out no-go areas for the courts."
Elias' statements suggest that the former Government had intended to make the property transfers but instead decided to make the transfers part of the legal settlement in order to avoid a challenge in the courts from Ngati Whatua.
Chris Finlayson, who was responsible for dealing with Ngati Whatua as former Treaty Negotiations Minister, flatly rejected that.
"It was an inevitable concomitant of the settlement that there would be legislation to give effect to it."
Finlayson also dealt regularly with Elias when he was Attorney-General, and he dismissed her comments in the judgment as "quite radical."
"She flies in the face of what has been mutual restraint and respect."
If Elias' thinking developed further over the years, Parliament would have to be "very firm" with the judiciary.
Finlayson said the three branches of Government [the legislature (Parliament); the executive (Cabinet); and the judiciary] had to respect one another and know the boundaries.
"And there are times, I feel, when some members of the judiciary have gone beyond that which is acceptable and they don't respect the institution of Parliament, and they should."
He believed Elias held a view that the judiciary was the superior branch of Government.
"All three branches of Government need to be deeply respectful of one another and know the boundaries and there is no one superior branch of Government at all."
Attorney-General David Parker declined to comment.
The issue of non-interference was referenced in a more mild way in the general judgment by the other Supreme Court judges when they say: "It is ... appropriate to sound a note of caution at the extent to which the principle of non-interference in parliamentary proceedings has been held to apply to decisions somewhat distant from, for example, the decision of a minister to introduce a bill to the House or from debate in the House."