The Prime Minister's former chief science adviser, Sir Peter Gluckman, is warning the Government that it needs to do more to respond to Covid-19.
In a tweet today, he said: "The evidence is mounting that the best thing NZ could do is make the hard decision to go to extreme shutdown now."
"The number of new cases coming from offshore means community transmission will get established without absolute precaution."
New Zealand is at level two on the official alert system - a full lockdown would mean the country would need to be moved up to level four.
Gluckman is the chairman of the International Network for Government Science Advice.
He is also the President-elect of the International Science Council.
His comments come just two days after he published a blog post – titled "Koi Tū, the virus and the future" – on the University of Auckland's website.
"The Covid-19-pandemic has brought into stark focus the interaction between science, experts, society, policymaking and politics," Gluckman said.
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He said the Covid-19 pandemic continues towards a potentially "horrific crescendo for many countries".
"The next 12 months, at least, will be first a period of managing an acute phase, followed by a containment and then a recovery phase," he said.
"Enormous disruption to social lives and sense of community, to family life, to mental health, to business, to economy and perhaps to social cohesion is inevitable."
He said much of the focus will remain on the short term, which is understandable.
"But it would be a terrible mistake if attention is not given now, and progressively, to the long-term matters that this epidemic will throw into sharp focus."
Gluckman said the characteristics of Covid-19 make it particularly "challenging and threatening" – more so than the Ebola, Sars, Mers epidemics.
"Yet the level of global preparation in recent years has arguably been limited by a failure to appreciate the significance of such warnings."
"Even now, there is rhetoric, at least in the USA, bemoaning decisions being made in the interest of public health that do not meet technocratic and plutocratic interests.
"There remains an array of denial and misinformation that bends the narrative to support political and economic interests."
Gluckman's call comes as the Teaching Council of Aotearoa New Zealand - which represents 100,000 registered teachers - has urged Prime Minister Jacinda Ardern to close down all schools.
The head of the Teaching Council of Aotearoa New Zealand - which represents 100,000 registered teachers - has written an open letter to Ardern this morning.
Lesley Hoskin said: "We have been communicating with teachers over the weekend and we've listened to their concerns.
"They want to support you and Aotearoa to flatten the curve. However, they want you to know, if you do not move now, they cannot see how they can protect their learners, themselves nor their loved ones at home."
Cabinet is meeting this morning to discus the next steps to combating the spread of Covid-19. Ardern will address media at 1.30pm.
Frontline heath workers are also urging the Government to move to level four urgently.