Advance New Zealand leader Jami-Lee Ross says our COVID-19 strategy has been "simply unsustainable" for New Zealanders, criticising the Government's decision to lockdown after cases reemerged in the community.

Ross, a former National Party MP, says New Zealanders should "learn to live with the virus" as he suggests new information shows the case fatality rate of COVID-19 is similar to the seasonal flu.

"It's the same ballpark, it's roughly similar," he told Magic Talk's Road to the Election.

"People are dying in the hundreds in New Zealand already with the flu every single year."

"Would we lock down an entire country for seasonal flu? No, we wouldn't."

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"Eventually, when the Government turns off their tap at the wage subsidy; businesses will fall over, people will lose their jobs, they will lose their homes, they won't be able to feed their children," Ross said.

The World Health Organization, however, says the mortality rate for COVID-19 appears higher than for influenza.

"While the true mortality of COVID-19 will take some time to fully understand, the data we have so far indicate that the crude mortality ratio (the number of reported deaths divided by the reported cases) is between 3-4 percent. For seasonal influenza, mortality is usually well below 0.1 percent," its website says. 

But Ross says if people are already dying in New Zealand with the flu every single year, it's "something we have to learn to live with".

"It's the cold hard reality of learning to live life with infections that can be managed."

The Government on Friday extended New Zealand's COVID-19 restrictions for a further 12 days.

"A cautious approach is the best long-term strategy," Prime Minister Jacinda Ardern told reporters.