Schools that refuse to comply with national standards requirements could face funding cuts, Education Minister Anne Tolley says.
The standards regime has come under fire from teachers, parents and academics, concerned at the speed of its implementation and the effects it would have on children who were falling behind.
Education Ministry figures show that, as of yesterday, more than a fifth of schools have submitted their annual charters without the required national standards targets.
Of the 1922 charters from English-medium primary schools analysed, 1503 complied with the requirement.
"Some schools have shown that they are having difficulty about how they set the targets, so we've had someone working with them, helping them develop that and we're just working through that process," Ms Tolley said.