School classes will be disrupted as thousands of teachers hold meetings about a funding proposal feared to be the return of bulk funding.
Education unions have launched a campaign aiming to pressure the Government to drop the proposed changes they say will decrease wages and force schools to choose between quality staff and other spending.
The funding proposal would change the way every state and state-integrated school is funded through the creation of a "global budget".
The Post Primary Teachers' Association (PPTA) and New Zealand Educational Institute (NZEI) launched a joint campaign at Wellington Girls' College yesterday morning.
NZEI president Louise Green said member meetings would be held on an unprecedented scale - 50 across New Zealand from September 5 to 16.
There would be some disruption to classes, but she hoped parents would understand the seriousness of what is at stake.
Prime Minister John Key had said the changes would not go ahead if the education sector was not supportive, Green said.
"We want to send a strong signal to Cabinet that the proposal is unacceptable."
Consultation documents published by the Government in June included giving schools a bulk allocation of funding - called a "global budget".
That funding would include cash instalments for school expenses and a credit system for salaries.
Principals would determine the split between cash and credit, and have the flexibility to make adjustments during the year.
Unspent credit would be paid out at the end of the year.
The Ministry of Education said the global budget would not be the same as the bulk funding of teacher salaries that caused widespread protest and was ditched in 2000.
Schools would receive credits for teachers, not funding to pay them, the ministry said.
Bulk funding was introduced on a voluntary basis in the 1990s and schools that opted in were given money linked to their allocation of teachers. They could then spend the money as they wished.
Supporters said the scheme gave schools more flexibility around staffing decisions.
But the NZEI has said the experience in the 1990s was that at some schools, new teachers were hired over experienced staff so money could be spent elsewhere.
PPTA president Angela Roberts has said the global funding proposal was bulk funding with minor changes.
The PPTA says the proposed changes could put pressure on schools to cut staffing to use money elsewhere.
The changes would also drive down teacher salaries, the PPTA says.
The documents are part of the Government's Education Funding Review, which has also proposed scrapping the decile system and targeting money at children deemed to be at risk.