In a sign little progress is expected to be made on a new four-year school funding deal, Education Minister Simon Birmingham has written to his state counterparts to request an extra meeting with them in June.

The meeting would lay the groundwork for Prime Minister Malcolm Turnbull to strike a final deal with state and territory leaders later that month.

Labor states and the federal government are blaming each other for the lack of funding certainty for next year onwards, which has alarmed the Catholic and independent school sectors.

Senator Birmingham told his state counterparts last September that he intended to replace the current school funding arrangements with a simpler and fairer model, but the government has yet to finalise its funding proposal.

School funding was expected to be finalised at a Council of Australian Governments (COAG) meeting this month but it was cancelled because two Labor premiers, Daniel Andrews from Victoria and South Australia's Jay Weatherill, could not attend.

In a letter to state ministers on Monday, Senator Birmingham said: "The Turnbull government has consistently made clear that the Prime Minister and and state and territory first ministers would finalise future school funding arrangements at COAG in the first half of this year.

"I have been working on a funding model that ensures the Commonwealth's record and growing levels of investment in schools is fairly and transparently distributed, allocated according to need and tied to reforms in school systems that are proven to improve student outcomes."

Victoria's acting Education Minister, Gayle Tierney, said Senator Birmingham was treating the states and territories "with contempt".

"Once again Simon Birmingham is treating the states and territories with contempt, offering only verbal briefings and no detail," she said.

She said the proposed meeting would be after the federal budget, making it difficult for state and territory education ministers to have any real input into a new school funding model.

"Victorian families deserve better than vague statements about 'further discussions'," she said.

NSW Education Minister Rob Stokes said he was still lobbying for the six-year Gonski agreements to be delivered in full.

"NSW has acted in reliance on the Commonwealth's commitment, and has a legitimate expectation that the federal government will honour their promise," he said.

Labor education spokeswoman Tanya Plibersek said: "Malcolm Turnbull knows parents, teachers, and state governments will be furious when they discover how badly their schools will be affected, so he is trying to keep it secret for as long as he can.

"Schools need more than a few months to plan for next year."