Groups representing school teachers, principals and trustees are worried the Government is considering changing the way it funds schools.
Treasury documents say officials were beginning to develop a system last year that would give schools more flexibility over their staffing.
School groups says the reference to flexibility is code for bulk funding schools for their teachers' salaries.
It is a policy that divided the sector and drew significant opposition when it was briefly introduced 17 years ago.
The Post Primary Teachers Association says bulk funding is a failed idea, and the Principals Federation warns that schools are in no state to accept a new funding system, regardless of what it is.
President of the Principals Federation, Philip Harding, says schools are in no state to accept further changes to their sector and says the government would be ill-advised to take those plans further.
He says the government should talk with school groups before planning major changes for the sector.
Education a high priority for Treasury
The papers show improving the system is the Treasury's highest priority and emphasise raising the quality of teaching.
The documents talk of a bold programme of change that will start this year and include new ways of funding schools and holding them and their teachers accountable for their performance, Radio New Zealand's education correspondent reports.
The papers suggest giving schools more control over teacher salaries, an echo of the bulk funding system teacher groups have fiercely opposed in the past.
They also show enthusiasm for centralising management of school property and for shifting school reporting from how well students are performing to how much they have improved.
Overall, they show the Treasury has a strong interest in the school system and little faith in increased competition as a way of improving performance.