On Tuesday, Jacinda Ardern's cabinet signed off on new rules that could see almost half of New Zealand's workforce face the sack if they don't get vaccinated against COVID-19.

Several industries are already covered by vaccine mandates.

Many workers at New Zealand's border, at prisons, in the education and health sector - including teachers, disability workers, doctors, pharmacies and nurses - must get vaccinated to keep their jobs.

Those mandates will now extend to workers at all businesses required to get vaccine certificates under New Zealand's next phase of the fight against COVID-19.

Under the vaccine certificate system, vaccinated Kiwis will receive a digital certificate showing their vaccine status which will allow them to access businesses deemed high-risk, such as retail and gyms.

Now, workers at those places will also need a certificate.

"We want workplaces open, customers safe and workers safe too ... this requirement means customers and staff are treated equally," Ms Ardern said.

The mandates will not stop Kiwis from accessing supermarkets.

"We do not want people who are not vaccinated to be precluded from accessing the basic necessities of life: food and health care and so on."

Workplace Relations Minister Michael Wood said mandates would cover roughly 40 per cent of Kiwi workers.

Non-vaccinated workers will be subject to a four-week notice period before they are sacked.

"I've spent my entire working life working for and with unions supporting the rights of working people so we don't move into these areas lightly, or without very careful thinking," Mr Wood said.

"But this is how we live together and the collective rights of people and workers in our society to be safe and feel safe when they're at work or coming into workplaces."

The government is also now asking employers to keep records of their workers' vaccine status, and to give them paid leave to get vaccinated if they need it.

The vaccine certificates and mandates will kick in later this year.

Australian Associated Press