National's leader John Key says protests by the union that represents primary school teachers are about supporting the Labour Party - not what is best for students.
Members of the New Zealand Educational Institute say they do not want anything to do with National's plan to pay good teachers and principals more to raise achievement across groups of schools.
Mr Key says newspaper advertisements and protests outside National Party offices were timed by the NZEI to co-incide with his party's education policy announcement today. He said the adverts promote an education policy very similar to the Labour Party's.
"This is the time to do the right thing by the children - not to do the right thing by the Labour Party. And that's what NZEI are doing, quite clearly, playing politics with the education of our children two weeks out from an election."
However, NZEI's president Judith Nowotarski said the timing is a coincidence.
"Our activity this morning is really building on the 93 percent rejection of the policy by our members a couple of weeks ago. We really want to get out into the public space that these are the things we're standing up for."