ew Zealand has been one of the few western nations to pursue a policy of elimination for Covid-19, drawing global praise and popular support at home for a swift and stringent lockdown that began three weeks ago. But now as the prime minister, Jacinda Ardern, decides how and when the strictest measures in the country’s national shutdown will ease, New Zealand’s comparatively low death toll and case rate have generated increasingly fraught and personal disputes between scientists about whether the lockdown has proven too costly. Ardern announced on 23 March that the government would move swiftly to implement a stringent national shutdown – at that point no one had died from the virus and a little more than 200 active cases – in the hope of preventing the catastrophic death tolls seen in Italy and elsewhere. On Monday she is due to signal whether her government believes four weeks of the most restrictive lockdown measures – which will expire next Wednesday – have been enough to flatten the curve and what the next steps will be. To date nine people have died of the virus in New Zealand, with more patients having recovered than there are remaining active cases. Modelling used by the government had projected 14,000 deaths if the virus remained unchecked, and Ardern has been lavished with praise by commentators overseas for averting that possibility. But domestically – as always – she faces a harder task in convincing the country to stay the course with the elimination strategy, said Jennifer Curtin, a politics professor at the University of Auckland. “There are a lot of people who are experts in this space in a way that we haven’t really seen in other crises that she’s had to deal with,” Curtin said. “This is a whole of society crisis and a whole range of interest groups are offering their opinion now.” Ardern has suggested that during the next phase of recovery from Covid-19 restrictions will be loosened only slightly. She has also pushed back at academics who are calling for a swift and total lifting of restrictions. “[It is] commentary that reflects our success to date in stamping out the virus as reason enough to take our foot off the pedal,” Ardern said. “It is not.” Among those calling for an immediate end to the lockdown is a group of scientists who provoked controversy this week by exhorting Ardern to reopen the country. The group of six, calling themselves Plan B, have claimed that a strategy of elimination is bound to fail and would generate worse economic and health outcomes than the virus itself. They have pointed to Australia, a favourite example of strict lockdown detractors, where a slightly less restrictive shutdown has seemed to result in a similar case rate of Covid-19 to New Zealand’s – though that conclusion has been disputed by a number of other scientists. “Prolonged lockdown is likely to cause greater harm than the virus to the nation’s long-term health and well-being, social fabric, economy and education,” said Simon Thornley, a public health lecturer at the University of Auckland, in a statement on behalf of the group. He added that New Zealand’s health system had “spare capacity” to deal with Covid-19, unlike in more populous countries. Echoing the group, the leader of New Zealand’s parliamentary opposition, Simon Bridges, wistfully referred this week to the takeaway coffees and haircuts Australians are permitted to access. New Zealanders can only leave their homes to walk, buy groceries or see a doctor. An editorial published by the group – which appeared to have sparked Ardern’s remarks on Tuesday – generated a backlash on social media where users said their proposition would condemn to death the elderly and those in ill health. “I’ve never experienced the level of vitriol that occurred over this,” Thornley said. Siouxsie Wiles, an associate professor in microbiology at the University of Auckland who has been a prominent government adviser during the crisis, accused Thornley and his group of “cherry-picking and misrepresenting evidence to support their position”. An article she wrote rebutting their points also generated a tirade of social media abuse – this time against her. “At the heart of Plan B is the belief that those who are more likely to die from Covid-19 should self-isolate so that the rest of us can get back to our normal daily activities,” Wiles said. “This sounds awfully like the UK’s original herd immunity strategy and look how that turned out.” No one would argue that the lockdown was not harmful to the economy but there was evidence from other countries that it was the “least worst option”, she said. More than 60 academics from Auckland university’s population health school signed a letter on Thursday saying they backed the government’s elimination strategy. Nick Wilson, a public health professor at the University of Otago, said scientists using their authority to suggest the economy should be reopened immediately were being “irresponsible in a time of such crisis”. “Normally it wouldn’t matter much, duelling academics,” he said. “But in a national emergency, which is what this is, if people are coming up and saying the government’s strategy is wrong, it is irresponsible not to back this with some very thoughtful work.” For his part Thornley is taken aback at the exhortations for him to be quiet. “I’m getting that sense that I’m out of order asking these questions, but to be quite frank these are probably the biggest policy decisions the government will make in my lifetime,” he said. “I want to be helpful. I could have not said anything and I would have been having an easier time.”