What happens when a proposed piece of legislation is judged by the attorney-general fundamentally to contravene individual rights? Surely, he informs his Cabinet colleagues, then proceeds to vote against it.
Not necessarily, suggests Andrew Geddis.
National MP Paul Quinn currently has a member's Bill before Parliament designed to take away the vote from all convicted persons while they are detained in prison.
However, Attorney-general Chris Finlayson has attached a notice under the New Zealand Bill of Rights Act 1990 to Mr Quinn's proposal.
This notice alerts Parliament to the attorney-general's opinion that the legislative proposal would strip individuals of a fundamental right in a way that cannot be demonstrably justified in a free and democratic society.
Mr Finlayson's reasons for this conclusion are that the Bill's objectives are not "rationally linked" to its means.
Because if the primary determinant of whether a person loses their right to vote is when they are sentenced, not what they are sentenced for or how long they are sentenced, it would have arbitrary outcomes.
You could, for example, see a person jailed for a month for not paying fines being unable to vote, while a recidivist burglar just released from 2 years in jail still casts a ballot.
Removing the individual right to participate in the most fundamental task of selecting who will make laws for our society in such a capricious and unprincipled manner simply is not acceptable in a country that calls itself a democracy.
So there is no surprise that the attorney-general acted as he did.
It was not even a close call.
Indeed, had he not attached a notice to this Bill, the entire system of "rights vetting" of proposed legislation would have failed catastrophically.
But here's the problem.
Having given his opinion that this proposed law limits a fundamental right in an unjustifiable fashion, it looks like Mr Finlayson will join his National Party colleagues in voting in favour of it at its first reading.
I don't mean to have a pop at him personally for this - other attorney-generals have done the exact same thing.
They are, after all, also MPs who are bound by caucus loyalty.
And Mr Quinn is a National MP, so it would be a slap in his face if National did not agree to support his proposal at least as far as select committee.
For that is all the first reading vote does; no doubt this Bill will quietly die there once its full flaws and inconsistencies are revealed.
Nevertheless, there still is something a bit off about the attorney-general one day giving his best considered advice that a proposed law is so inimical to individual rights that it ought not to find a home in the statute books of a free and democratic society, and on the next going into Parliament and voting to allow it to proceed towards enactment into law.
Other MPs don't face the same problem.
A Bill of Rights Act notice is just the attorney-general's view of the matter.
Other MPs are fully free to accept or disagree with it (although we should expect them, as a matter of legislative best practice, to at least consider the attorney-general's view and come up with reasons why they think it is wrong).
So if MPs choose to vote for a Bill that the attorney-general believes unjustifiably limits rights, that only means that they believe the rights limit is justifiable.
I have no problem with that happening.
And it happens quite often: in the 20 years the Bill of Rights Act has been in place, fully half the Bills attracting a section seven notice have passed in an unchanged form.
With respect to Government Bills, the enactment rate is 90% But the attorney-general is in a rather different position.
As a law officer, his job under the Bill of Rights Act is to warn Parliament about proposed legislative measures that he believes unjustifiably trench on fundamental individual rights.
For him to then, as a parliamentarian, vote in favour of those measures becoming law completely undercuts the message his warning is meant to send.
Why take the attorney-general's opinion seriously when he himself doesn't think it important enough to follow? After all, he can hardly say, "as attorney-general, I believe this is an unjustified limit on rights, but as an MP I believe it is fine".
So here's my proposed solution.
We need to develop a constitutional convention in New Zealand that the attorney-general will vote against, or at least abstain on, the first reading of any Bill in respect of which he has issued a Bill of Rights Act notice.
A vote against would be preferable, but I retain the abstention option in recognition of the political reality that the attorney-general cannot oppose measures brought before the House by his Cabinet (or caucus) colleagues.
It may be that such a convention would not appreciably alter the fate of any future legislation.
But it would put an end to what otherwise is a practice that just cannot be justified on any principled grounds.
• Andrew Geddis is associate professor of law at the University of Otago.