New Zealand's biggest teachers union fears the quality of early childhood education will slip beyond repair after six years of a funding freeze.
New research by Infometrics shows $260 million has been cut from early childhood education (ECE) funding since 2010.
New Zealand Educational Institute national secretary Paul Goulter says many teaching programs have been cut as a result.
"That means the quality of the learning is correspondingly reduced. As a result, the quality is diminished that makes it harder for those kids, and that effect tracks right throughout their education career.
"The Government's refusal to fund the early childhood sector properly has meant that the quality of the teaching and learning those kids actually are meeting is not as good as what it should be. Teachers right throughout the sector are really annoyed."
The Government says it has doubled early childhood education funding since 2008, increasing it every year.
But NZEI says the equivalent of $58,000 a year in funding has been cut from every ECE centre in the country over the last six years, as per-child funding has not been adjusted to match inflation.
"This Government's proudly claiming it's going to be able to run a surplus," Mr Goulter says.
"There's no better place to put any surplus other than into education, and we know that one of the biggest bangs for your buck lies in investing properly in early childhood education."
He says recent funding increases are only matching the number of new enrolments.
Labour's education spokesperson Chris Hipkins says they're committed to properly funding early childhood centres.
"On behalf of the Labour Party I was more than happy to sign up to the NZEI's Have a Heart Pledge committing us to properly funding early childhood education, dealing with ballooning class/group sizes, and returning to the goal of having 100 percent qualified teachers in centres."
Education Minister Hekia Parata says 97 percent of centres already have 80 percent or more qualified teachers on staff, and per-child funding is in the top-third of the OECD.