Despite boasting a huge surplus in Tuesday's budget, in a state where preschool and childcare fees are the nation's highest the NSW government is still spending the least per child on early childhood education of any state.

In Wodonga on the Victorian side of the border, the childcare centre run by not-for-profit Goodstart Early Learning gets $3000 per child from the Victorian government each year. But across the bridge in Albury, their four centres receive $300 per child from the NSW government.

It's a border quirk that reflects the big differences in how state governments prioritise early childhood education.

"Our preschool rooms in Victoria and Queensland are now increasingly better resourced than our preschool rooms in NSW because we have access to more funding," says Goodstart's advocacy manager John Cherry.

"That means preschool programs in Victoria and Queensland have got access to more teaching resources, more staff development for teachers and potentially more excursions which aren't available to NSW children."

A broad range of experts, from education academics to the Productivity Commission and even the federal government agree: preschool access for all is the best and cheapest way for governments to level the playing field for kids starting school.

But NSW still lags far behind the other states, with just 82 per cent of four year olds enrolled in the minimum 15 hours a week.

"The problem is that NSW families cannot afford [15 hours per week] because fees are too high because the NSW government's own funding of preschools is too low in the first place," says Diane Lawson from the Community Child Care Co-operative. "Unless the NSW government invests more money in the first place, NSW children will continue to miss out."

Advocates say this week's budget does nothing to change that.

Tracy Howe from the NSW Council of Social Services said while there was much to be positive about in the budget it was disappointing that early intervention initiatives and early learning continued to be overlooked.

"We know too many children in NSW are missing out on the best possible start in life as investment in early childhood education and care fails to reach the most vulnerable. NSW has by far the lowest proportion of children attending early childhood education in the year before school (82 per cent), is the state with the worst performance on the proportion of disadvantaged children in early childhood education (72 per cent), and has the least affordable fees."

The Auditor-General revealed recently that the NSW government has not spent $350 million it budgeted for early childhood education since 2011-12.

Early childhood minister Leslie Williams said that was because the government had to manage the uncertainties in the receipt of Commonwealth funding under the Universal Access National Partnership, which relies on NSW meeting various benchmarks.

NSW receives around $135 million a year from the Commonwealth for preschool programs. This is contingent on performance benchmarks such as getting 95 per cent of all children into 600 hours, meaning that federal funding is at risk if NSW doesn't lift its game.

Ms Williams defended the government's record.

"Over the past four years the spend on early childhood education and care by this government has increased by 45 per cent," Ms Williams said.

"In January 2014, funding for community preschools increased by 20 per cent to $150 million per annum ... [and] the government announced an additional $83.5 million in initiatives in November 2015. This investment will help children across NSW to access the lifelong benefits that come from 600 hours of preschool education in the year prior to starting school."