An Auckland headmaster says the government's decision to partially reopen schools is totally irresponsible and teachers are being asked to babysit, not educate.
Under alert level 3, students up to year 10 can return to classrooms.
The Prime Minister says more people will be allowed to go back to work under level three and children under the age of 14 cannot legally be left home alone.
But teachers and students will still have to keep their social distance. Auckland Grammar Headmaster Tim O'Connor said he had no idea how it would all work.
"It is, from my mindset, one of the most irresponsible decisions for New Zealand education in my time as headmaster of the school."
O'Connor said that if it's safe to partially reopen a school under alert level 3, the government should be targeting the students who are most in need in the secondary sector - the Year 12 and 13 students who are sitting NCEA, Cambridge, or International Baccalaureate.
"The government's not making a decision about education, it's making a decision about how to provide child care for reopening the country.
"That, to me, is more irresponsible than David Clark going out for a mountain bike ride or Winston Peters fishing from his front lawn."
O'Connor said it would be too complex for teachers to have to teach students who turned up for school, as well as those that didn't.
"Just be honest about it and say schools have to provide child care services. Say we're not educational institutions for the next month.
"This is not about education at all. It's not a teacher's job to be a babysitting service - but, if that's what the government wants, then be honest about it. Don't pretend."
He said schools should have been consulted so plans could be in place to teach students across campuses and implement safety measures such as reduced contact and social distancing.
"What we've been given here is partial bits of information. The Secretary of education [Iona Holsted] emailed principles at about 4pm to say they'd start working with schools more next week on the practical issues. Well, there's a whole pile of practical issues."
O'Connor said he only found out about the level 3 scenario today, at the same time as the rest of New Zealand.