In short:

The NSW government has pledged 100 new preschools will be open for 2027, but has refused to say how many would be accepting children.

The opposition says families need certainty in where their children will be enrolled.

What's next?

The independent NSW Early Learning Commission has to approve the new preschools.

The Minns government's pledge to have 100 new preschools operating on "day one, term one" in 2027 could be in doubt, after the NSW education minister refused to say how many would be open to students by deadline.

Prue Car joined the premier, Chris Minns, to announce the opening of a new public preschool at Yagoona, located alongside the local primary school in Sydney's south-west.

It is one of 100 preschools the government had promised, offering fee-free early education to children in the year before they start kindergarten.

In May, Ms Car said "every single one" of the public preschools would be "open and operating" from the first day of term in 2027.

On Monday morning, Ms Car confirmed all the preschools would be "finished" by then.

However, she repeatedly refused to say how many would actually accept children on day one of term.

Ms Car: "Our commitment was to open 100 public preschools by day one, term one, '27.

"And they'll all be finished by day one, term one, 2027."

Journalist: "So they'll be open to students?"

Ms Car: "They will be open by day one, term one, 2027."

Journalist: "Will they be accepting preschool students on day one, term one?"

Ms Car: "We're actually, I mean, the opposition likes to say, 'Will these be open?'

"I'm going to be really clear. These are actually popping up in six months. They will be open day one, term one, 2027."

Regulatory approval needed

When asked whether she could provide a rough estimate about the number of the new preschools that will be open to students, Ms Car declined to do so.

"We will not be backward in coming forward about when these preschools open," she said.

Shadow Early Education Minister Felicity Wilson said families were entitled to know whether all the preschools would begin teaching on day one of the new school year.

"Families need certainty,"she said.

"They need to know where their child will be enrolled."

In a statement on Monday afternoon, Ms Car said "all 100 new public preschools will be delivered and ready to accept students by Day 1, Term 1, 2027".

Each preschool will need the approval of the independent NSW Early Learning Commission, and Ms Car declined to say whether she anticipated delays during that process.

Some preschools are ready early

Despite doubts over the readiness of some public preschools, the government has celebrated the opening of 14 new centres in time for term four.

Many are in Western Sydney, including Cartwright, Granville East, Guildford West and Villawood North.

New regional preschools include Leeton and Moorland.

Seven other public preschools are already open to students, meaning the government is already one-fifth of the way to reaching its 2027 target.

The premier said locating the preschools alongside primary schools would save parents time.

"It's also a great opportunity for kids who are enrolled in the preschool to have some kind of exposure to big school and to make that leap from early childhood education to kindergarten a little bit easier for parents," Mr Minns said.

Ms Car said building public preschools was one of her proudest achievements.

"The Liberals and Nationals didn't build one in 12 years, and we are building 100 and we are very, very proud of that."