In a rare return to the political fray, Sir John has reset the national conversation on New Zealand's pandemic planning with a widely published opinion piece.

Sir John, prime minister from 2008 to 2016, says New Zealand needs an Australian-style roadmap to re-opening borders and restoring freedoms.

"There has been no coherent plan shared with the public for when or how these might be achieved," he writes.

"The only urgency we've seen for months is an enthusiasm to lock down our country, lock up our people and lock out our citizens who are overseas."

In a blistering attack, the National ex-PM said Ms Ardern chose "the North Korean option" and was "ruling by fear".

Sir John said Ms Ardern's government should be focused on restoring the rights of New Zealanders - including those he said were "stateless", unable to return home due to quarantine restrictions.

The 60-year-old also gave his own five-point plan, which includes both carrots and sticks: he advocates financial incentives to boost jab rates, and barring the unvaccinated from licensed premises.

"Reassure people that living with the virus is possible, as long as you're vaccinated," he urges Ms Ardern.

To date, the prime minister has resisted setting a timeline on border re-openings - including paused trans-Tasman links - or abandoning lockdowns.

Plans to introduce a domestic vaccine passport and lessen quarantine restrictions all remain in the policy development phase.

On Monday, Ms Ardern announced progress towards reopening on two fronts.

Firstly, the government will run a pilot isolate-at-home program for 150 business travellers beginning next month, which could help reduce reliance on quarantine hotels.

Secondly, it will also allow seasonal workers from COVID-free Vanuatu, Samoa and Tonga to skip quarantine when they arrive from next month.

However, her government's chief COVID response is to stay laser-focused on lifting vaccination rates.

She has embraced a 90 per cent target - including 90 per cent of vulnerable groups and isolated communities such as Maori, Pasifika, and regional Kiwis - that would see New Zealand avoid the worst health outcomes from future outbreaks.

Ms Ardern's health focus is in keeping with her governing style through the pandemic, which has been domestically popular and internationally lauded.

"I'm proud of our team's response," Ms Ardern told TVNZ.

"We've had some of the lowest case numbers in the OECD, (and) death rates, and had our economy back in the spot at pre-COVID levels faster than most others."

She shrugged off Mr Key's attack, jokingly telling Radio NZ she thought she might be introduced as "the military leader of the hermit kingdom".

However, her inability to give Kiwis future certainty heading into the summer leaves room for political opponents to sell their vision.

It is telling too, that the former prime minister's attack has captured the attention of Kiwis - whereas current leaders of his party fall flat.

Incumbent opposition leader Judith Collins has struggled to inspire Kiwis, her party floundering in opinion polls well behind Ms Ardern's Labour.

Ms Collins' National party will publish its own route to reopening on Wednesday, and will hope a slice of Sir John's enduring popularity might shine on their plans.

Australian Associated Press