A survey leaked to Newshub shows more than a third of the country's secondary school teachers may not go back to work under alert level 2.
The leaked internal PPTA survey of secondary school teachers found 30 percent of the country's 25,000 secondary school teachers may not go back to school at alert level 2 and six percent say they definitely won't go back.
That equates to 1500 teachers saying they definitely won't be going back to school under level 2, and 7500 potentially not returning. If all 36 percent didn't return, that would be 9000 teachers not at school.
The reason most cited was health concerns, including things like pregnancy, diabetes, and cancer.
The PPTA said that even if there was a "really well-managed return", secondary schools could be missing six teachers each on average, "if the messaging, school plans and availability of childcare do not meet the needs of teachers".
The survey was undertaken before Thursday's announcement of what alert level 2 will look like, because the PPTA said "waiting for more clarity would not have allowed enough time to react to any potential staff shortages".
Little School early childhood centre owner Maria Johnson said she had several staff who said they wouldn't be returning to work under level 2.
"They're spread across Auckland and Wellington," said Johnson.
"I've got a team member who's pregnant, I've got a team member that has a partner who's undergoing chemotherapy, and I've got a team member who's boarding with older people and they've actually said she can't come back."
PPTA president Jack Boyle said his unions focus will be on "supporting them over the next two weeks, or however long it is before we move to alert level 2."
For those who will return, schools are trying to make them safe but there are no guarantees.
"We're getting hand sanitiser [and] disinfectant for cleaning the desks," Glendowie College principal Richard Dykes said.
"We're clearly not going to be as sterilised as an intensive care unit, you know, we are a school."
But even compared to the likes of bars and restaurants, which will be held to stringent rules, there's no physical distancing requirement for schools - just a recommendation to stay one metre apart.
The Ministry of Health says "if you can smell the person's breath or feel that you are in that 'moist breath' zone, move a little further away".