The Government has no plans to re-write the law despite the High Court ruling that the first nine days of the nationwide Covid lockdown were unlawful, though justified.

New Zealanders were not actually required by law to stay at home in their bubbles until April 3, more than a week into lockdown, today's ruling has found.

"Even as this country returns to a state of semi-lockdown, there is one thing on which most commentators are agreed. The decisions taken by the New Zealand Government in March this year to "go hard and go early" were the right ones," said the High Court decision, released this afternoon.

"Even in times of emergency, however, and even when the merits of the Government response are not widely contested, the rule of law matters."

That was why Wellington lawyer Andrew Borrowdale sought a judicial review of the lockdown decision, asking for declarations of illegality in relation to three aspects of the Government's initial Covid-19 response.

The first focused on public announcements made by Prime Minister Jacinda Ardern and other officials during the first nine days of lockdown.

The other two aspects related to orders made under the Health Act 1956 by director general of health Ashley Bloomfield on March 26, April 3 and April 27, and the definition of "essential services". Those two aspects were dismissed by the court.

The first order made at the start of level 4 lockdown was a ban on congregating and the closure of non-essential businesses, but it did not require people to stay home and in their bubbles.

Those obligations were instead conveyed to the public by Ardern and other officials in media briefings from March 23 onwards. Borrowdale argued these further restrictions were not "prescribed by law" and therefore unlawfully limited some of the public's rights and freedoms under the New Zealand Bill of Rights Act

The court has agreed the statements conveyed New Zealanders were required - under threat of police enforcement - to stay at home in their bubbles, despite the fact it was not legally supported at the time.

Until Order Two came into effect on April 3, those restrictions were an unlawful limit on Kiwis' rights and freedoms.

The court did not find any laws were "suspended", and said the power to impose the restrictions existed but was simply not used until April 3.

The court recognised the state of emergency went some way to explaining what had happened, and declared the requirement was still a necessary, reasonable and proportionate response to the Covid-19 crisis at the time.

In an affidavit to the court, Bloomfield described the approaching wave of the pandemic, and said there was "only one shot" at stamping out the virus.

"We realised that 'go early' had changed to 'go right now', and there was no time left. What we thought could be done in two weeks or two days had to happen now: it was quite literally now or never," he said.

"The absolute priority was to get the lockdown in place and that drove every aspect of what we did over that period: we needed to move, and had no time to sort out the exact details. Some things would have to get sorted out later."

In the court decision, justices Susan Thomas, Geoffrey Venning and Rebecca Ellis concluded the effect of the statements from Ardern and other officials caused New Zealanders to believe they were required by law to stay home and in their bubbles when - for the first nine days - it was not the case.

They made a formal declaration that the statements made in the initial part of lockdown were not lawful, and therefore limited the rights of New Zealanders.

It's believed there will be few, if any, prosecutions affected by today's findings.

The other challenges

Bloomfield's first three orders under section 70 (1) of the Health Act 1956 forbade congregations, except for those with social distancing, required the closure of non-essential businesses, and required all people to be isolated or quarantined at home.

Borrowdale argued the orders went beyond the "special" authorising powers in section 70 and that they, too, unlawfully limited the New Zealand Bill of Rights Act.

But the court found the spread of the virus, a need to protect public health, and the nature and history of emergency powers under section 70 reinforced the need for a liberal interpretative approach to the legislation.

They said the section was meant to be read as applying to circumstances as they arise, and that the powers clearly contemplate the restriction of fundamental rights in a public health emergency.

Borrowdale also said Bloomfield had exercised an unlawful delegation of his powers because it had been left to the Ministry for Business, Innovation and Employment (MBIE) to define what an essential business was.

But the court found Bloomfield had clearly defined what essential businesses were, and that MBIE's online list served only as interpretative and advisory.

Attorney-General says no need for law change

Responding to the ruling, Attorney-General David Parker said the Crown's position was that it had won on the most significant points.

There were no plans to change the law used to introduce the lockdown, he told reporters.

Parker said the Government always thought it was "acting legally" the entire time.

The Government didn't believe it was necessary to put the stay at home order down in writing at the beginning, he said.

There were 15 charges laid under the Health Act during that nine-day period, and none were affected by the change in order on April 3.

"I think it's very easy to look back and go over ever word with the benefit of hindsight," Parker said.

In an earlier statement Parker said no decision had yet been made on any possible appeal of the judgment.

He said was "a significant judgment in which all the health orders issued ... were lawful.

"The challenges that the orders made to close premises New Zealand wide, except for essential services, to prohibit congregating in outdoor places and to require people to self-isolate and stay at home have all failed," Parker said.

"It is very satisfying that these orders have been upheld. We can be confident in the orders made and enforced," Parker said.

"However the court did find that there was a breach of the Bill of Rights Act in the first nine days of the Alert Level 4 lockdown, because the original oral request for people to stay home and in their bubbles was not put in a formal order until 3 April.

"Importantly, though, the court found that the requirement to stay home and in their bubbles was a necessary, reasonable and proportionate response to the COVID-19 crisis at that time."

The current lockdown orders made under the Covid-19 Public Health Response Act 2020 are not affected by the judgment.

Parker said in a statement the Court had stated the question was finely balanced. While it found an unlawful limitation on rights and freedoms for nine days it said "that must be seen in the context of the rapidly developing public health emergency the nation was facing".

"It found the imperfection from 25 March to 3 April was cured by the 3 April order," Parker said.

The court also made the point that its findings have to be kept in perspective: the situation lasted for just 9 days and occurred when NZ was in a state of national emergency fighting a global pandemic.

The Court also rejected the challenge that the Prime Minister had attempted to suspend the law, saying that the power to require all New Zealanders to stay at home was a power that could have been (and was, from 3 April) exercised by a health officer under the Health Act, Parker's statement said.