Health fears and lack of demand are likely to keep many early childhood centres shut when schools partially reopen next week.

Sector leaders say many centre owners, teachers and parents were not convinced it is safe to reopen, despite government assurances the chance of a Covid-19 outbreak in an early learning service was extremely low.

However, kindergartens and some other centres say they were confident they could join schools in reopening safely for the children of people who needed to return to work at alert level 3.

Centre owner Maria Johnson says she had called more than 200 families that send children to her seven early childhood centres and very few wanted them to reopen.

"A lot of our families do fall into the essential workers category, and they want to keep their children at home until they feel it is safe to send them back," she says.

Maria says teachers are also nervous about the health risk of reopening.

It would not be viable for early childhood centres to run with just a few children present, she says.

An expert on public health in early learning centres, Mike Bedford, hasd been urging the government not to reopen centres.

He says he agreed the success of the level 4 lockdown in reducing the Covid-19 outbreak has greatly lowered the risk of infection in early childhood centres, but the risk still existed.

"You simply can't say that an early childhood centre is safe in Covid-19, that just doesn't make any sense.

"Early childhood centres have never been safe from infection and there remains certainly questions over asymptomatic spread."

Mike says he was not persuaded by World Health Organisation (WHO) evidence from the Wuhan outbreak that the government had cited as proof there was little risk to small children.

He says the numbers attending early learning next week must be as low as possible.

Mike says he is concerned the government wanted children to stay in bubbles of 10, but it was not limiting the total number of children that might be present in an early learning centre.

Early Childhood Council chief executive Peter Reynolds says he was also not convinced by the WHO evidence and he did not want to see an early learning centre become the centre of a new infection cluster.

He says many centres would not reopen next week, but others would.

"There's still a lot of anxiety out there, so there's a strong number out there saying, 'we're not prepared to open' and there is a number out there who say, 'no we're going to throw caution to the wind and give it a go'."

The deputy chief executive of early childhood company Best Start, Fiona Hughes, says about five to 10 per cent of the families that use its 260 centres had indicated they wanted them to reopen and most would.

"I'm a little doubtful, because I think numbers are very low, that all of them will open, but where there's a need that's our duty to the community."

NZ Kindergartens chief executive Jill Bond says its member associations were preparing to open some of their kindergartens next week.

She says Ministry of Health and Ministry of Education advice had reassured associations that it was safe to reopen for a small number of children.

"We are assuring families that if they need to go back to work, their child will be safe."

Jill says families could also send their children to kindergarten for other reasons.

"There will be some families who, for personal reasons, will want their child to return to the routine of kindergarten now. We're saying that's absolutely fine."

RNZ.