The legality of the COVID-19 lockdown in New Zealand has been thrust into the spotlight. This should not be a surprise—the lockdown is the most drastic exercise of government power we are likely to experience in our lifetimes.

It is right we question whether the Government acted lawfully.

Academic colleagues argue justification under the Health Act 1956 is thin. The Opposition has hinted it believes the lockdown was not lawful, and there is a case now in the High Court.

The Attorney-General responded to the criticisms in a Facebook speech that set out his belief in the lockdown’s lawfulness. Our view is the Health Act can be read with a more benevolent eye to provide a defensible legal basis for the isolation orders issued by the Director-General of Health.

We fear some of the current public debate (and we do not include our colleagues’ original and measured post in this) risks presenting the arguments as clear cut or impugning the fidelity or competence of officials and their commitment to the rule of law.

Our government ministers and officials must interpret and apply the law as best they can and in good faith—there is no reason to suspect they have done otherwise, even if courts subsequently take a different view of the law.

Interpretation of legal provisions, especially determining the scope of power granted to ministers and officials, turns on a range of factors: the text of the key section, along with the statute’s scheme, history and purpose, as well as the wider context of our legal system.

Section 70(1)(f) of the Health Act gives the Director-General power to require persons to be isolated or quarantined to prevent an outbreak or spread of an infectious disease. Contrary to our colleagues, we believe this power can be read generously to allow generalised orders isolating all members of the public.

On its face, the text of (f) and the reference to “persons” means the power is wide enough to enable generalised orders. There is nothing requiring it be confined to people who are infected.

The legislative scheme pulls in either direction. On the one hand, the contrast with the power in section 70(1)(m) to close premises—subject to obligatory public notice—suggests (f) should only be used on an individualised basis. On the other hand, Part 3A of the Health Act contains an extensive regime for managing individualised quarantine of infected persons, leaving more room for (f) to have general application.

The purpose and history of the infectious disease regime probably favour a generous reading, especially in the light of the dangerous outbreaks at the start of the 20th century—such as typhoid and plague—that saw these powers first granted to medical experts.

The New Zealand Bill of Rights Act 1990 and our common law traditions favour rights-consistent interpretation of ambiguous wording. But neither dictate a clean sweep for individual rights in the case of a public health statute that inevitably anticipates rights being so limited. The Bill of Rights Act direction is always subject to justified limitations and there is an argument that the principle of legality should similarly be injected with some sense of reasonable limits.

The Director-General and Cabinet have been engaged in a delicate tango navigating the Director-General’s independence on public health matters and the need for democratic input into the dramatic restrictions on our lives. Economic and social considerations are beyond the Director-General’s usual domain and expertise—Cabinet’s all-of-government perspective enriches the decision-making. The extra-legal alert level framework adopted for the pandemic is a way to give Cabinet voice on lockdown expectations, while protecting the Director-General’s independent judgment on medical matters.

We also believe that, on balance, the orders closing premises were legitimate under the section 70(1)(m) power. There are concerns the power to close “all premises … of any stated kind or description” was used to close all premises in the country. But the orders did not close all premises. Premises of essential businesses providing the necessaries of life remained open. And there is little in the wording to suggest this special power could not be used in an aggregated and comprehensive fashion.

Sometimes this power may have been used inconsistently in the Level 4 lockdown, especially in the earlier days when there was genuine uncertainty about what was “essential” and the website listing categories of business kept evolving. But that does not go to the general legality of the use of (m) power.

We, like others, have been struggling with these provisions over the past two months.

We agree the provisions are not as clear and firm as they could have been in authorising what the Government has had to do—and the arguments around their interpretation are probably finely balanced.

But this is not an uncommon reality of modern government or statutory interpretation. Indeed, the role of officials and courts is very often to make basic judgment calls about how far clunky wording can be massaged or stretched to circumstances beyond what the drafters had in the front of their minds—and when trying to do so goes too far.

When basic liberties are involved, officials and courts should err on the side of preserving those liberties. But they must also take heed of the purpose of the statute and the community the law protects.

We think judges might have a degree of reluctance about unravelling the acutely important and largely effective lockdown regime on a contestable point about legal interpretation.

This is an adaptation of an article on the blog of the UK Constitutional Law Association.

Associate Professor Dean Knight and Professor Geoff McLay are in the Faculty of Law at Te Herenga Waka—Victoria University of Wellington.

Read the article on Newsroom.