Education Minister Simon Birmingham says the funding injection will extend the national partnership on early childhood education into 2019, covering more than 348,000 children.

This will ensure children have access to 15 hours of quality early learning in the year before school.

The announcement comes as new data shows nearly one in 10 of the children the program was supposed to support weren't enrolled in preschool.

And only around 70 per cent of children enrolled in dedicated preschool were attending for the full 15 hours a week.

"There's clearly an opportunity to work with states and territories to ensure our funding for preschool is best supporting all children, especially those who most need it," Senator Birmingham said.

He said too often students not getting the full 15 hours of preschool came from disadvantaged backgrounds, raising the potential for a "lost generation" of children who start school too far behind their counterparts.

The extension would provide time to work through such issues with the states, but the federal opposition is not impressed.

"Whilst Labor welcomes this last minute stop-gap, it's a weak effort by the minister who has once again left uncertainty in the sector and uncertainty for families," Labor MP Amanda Rishworth said.

"If the Turnbull government were serious about giving our children the best possible opportunities in life they would ensure long-term funding for four-year-old preschool was secured."

Senator Birmingham argued states must do more to lift attendance rates before the end of 2019.

"We're not going to give the states a blank cheque when they're failing to actually get kids who could benefit the most to turn up to preschool," he said.

"We want to work with the states to make sure we can target those children with disadvantage, lift those attendance rates, and get over the next couple of years better data and better attendance that can provide the basis to better structure the preschool arrangements for the long term."