The head of the Post Primary Teachers' Association says teachers should be wary of privatisation deals under a National Government.
But PPTA president Robin Duff also told a conference in Wellington that the union has been let down by the current Labour Government on a number of issues.
He said the interest shown by the National party in public private partnerships for the building of new schools, raises concerns about who would pick up the tab for any disaster when a such a deal came unstuck.
Mr Duff also criticised National's policy of giving more money to private schools.
But there were also barbs for the Labour government.
Mr Duff said the union would never forgive Labour for its treatment of teachers without degrees and for what he called the Government's cynical use of pay parity to hold down all teacher salaries.
