New Zealand cannot risk a new Covid-19 outbreak, so alert level 2 in Wellington should stay in place for two more weeks, says Auckland University professor of medicine Des Gorman.
He said the government needed to weigh the risks carefully, before it delivered its verdict today on easing Wellington's level 2 restrictions and re-opening the trans-Tasman travel bubble.
Wellington, Wairarapa and Kāpiti Coast were put in alert level 2 on 23 June, after two Australian tourists who had visited attractions in the capital tested positive with Covid-19.
Wellington is due to move out of level 2 at midnight tonight if there are no further changes from Cabinet.
Gorman said the city should stay in level 2 for another two weeks, particularly given the Sydney man had the more highly contagious Delta variant.
"That gives you some confidence there's not going to be a tail that's going to come back and bite you," he said.
"While that clearly is not the sort of news that restauranteurs and other people in hospitality want to hear, the last thing you want in the Wellington region is to discover an outbreak and then have to go into level 3 or level 4.
"It's not particularly difficult to imagine there may be one or two smouldering cases out there."
Quarantine free travel from all Australian states and territories was paused on Saturday night until just before midnight tonight, after a Covid-19 outbreak in New South Wales.
Gorman said the pause on the Australian travel bubble should also remain for another two weeks.
"The rationale for that conservative approach is that 90 percent of us aren't vaccinated, we have very limited contact tracing capacity, and from a financial point of view, our economy is really unable to sustain too many more level three or level four lockdowns.
"Our unvaccinated state just leaves us so incredibly vulnerable, particularly to something like the Delta variant.
"In that context ... you have to put the welfare of the country ahead of the welfare of individuals."
Although no cases had recently been reported in South Australia, it shared a border with New South Wales, so the outbreak there could easily spread, he said.
Repatriation flights followed by quarantine for travellers could be needed, he said.
It was likely the government would come under pressure to take a riskier approach, so another agency should be responsible for making decisions about alert levels and travel restrictions, Gorman said.
"What this demonstrates very clearly is why politicians should not have governance roles when it comes to managing health emergencies like this, because no matter how hard they try, they are vulnerable to electoral risk - they need to be popular.
"It's very hard to make completely objective decisions when in two and a half years' time, you have to win a popularity contest.
"This is an impossible position for them to be in, but the solution is actually to hand governance over to people who are not subject to those stresses," Gorman said.