Prime Minister Scott Morrison says the government's medical advice confirms social distancing requirements do not apply to classrooms, clearing the way for students to return to school.

While Australians have been told to keep 1.5 metres apart, or two arms' lengths, Mr Morrison said the Australian Health Protection Principal Committee (AHPPC) had determined students did not need to abide by that advice in the classroom.

"The advice cannot be more clear than that. The 1.5 metre in classrooms and the four-square-metre rule is not a requirement of the expert medical advice in classrooms," Mr Morrison told reporters after a meeting of the national cabinet.

The decision comes as debate continues on whether it is safe for schools to reopen to all students.

Schools have remained open only for children of essential workers, with most students continuing their learning online at home.

New South Wales announced plans this week to return to face-to-face teaching in a staggered fashion from 11 May.

Queensland kids should be back at school and the only reason they’re not is because the Premier is running scared of the militant QTU. Premier @AnnastaciaMP it’s time to put the interests of our Qld kids ahead of the union bosses. — Peter Dutton (@PeterDutton_MP) April 24, 2020

Victorian Premier Daniel Andrews has warned that fully re-opening schools would only spread the virus with tens of thousands of families having to move around the state to pick-up and drop-off children.

Queensland Premier Annastacia Palaszczuk is standing firm that students other than the children of essential workers should not return to school before 22 May.

That has prompted Home Affairs Minister Peter Dutton to accuse her of pandering to the teachers union.

"Queensland kids should be back at school and the only reason they're not is because the premier is running scared of the militant QTU," Mr Dutton tweeted on Friday.

Queensland Teachers Union president Kevin Bates told SBS News the sudden change in medical advice was "perplexing", but would now have to be considered.

“We acknowledge and accept the advice for what it is, but there is still a question mark for us about how we’ve gotten to this position,” he said.

READ MORE Teachers Union president tells Scott Morrison to keep out of schooling debate

Mr Bates said many teachers still found it hard to understand why the 1.5 metres rule would not apply in a classroom setting.

"What we don’t understand is why when you’re dealing with children who can’t go and visit their grandparents in an aged care facility," he said.

"Why ... in my classroom that social distancing requirement doesn’t matter."

Chief medical officer Brendan Murphy said on Friday there was no evidence of significant transmission amongst children in schools.

"So we think the community risk of having children together in a classroom is low," Dr Murphy said.

"Most children who have contracted the virus in Australia have contracted it in the family home. They have not contracted it in the school environment."

The national cabinet has also agreed to develop national principals to guide the return of sport and recreation.

"That is such an important part of our way of life here in Australia, and the principles can help guide decisions by states and territories in the future," Mr Morrison said.