State Education Minister James Merlino said it was "highly unlikely” a funding agreement would be in place before Victorians went to the polls in November. He blamed the situation on "chaos" in Federal Parliament.

Schools say the uncertainty is making it difficult for them to plan their programs and staffing arrangements for next year.

Days before a meeting of education ministers in Adelaide, Mr Merlino said his hopes of securing a funding agreement had been dealt a blow by the recent turmoil in Canberra.

“We have been handed a new federal minister in the middle of negotiations and there is no end in sight for the ongoing fight that they have been having with Catholic and independent schools,” he said.

“It is highly unlikely we will have a funding deal with the federal government in place before we enter caretaker mode at the end of October."

School funding will be the focus of a meeting of education ministers on Friday, with newly appointed federal Education Minister Dan Tehan saying he hoped to strike a deal with the states in coming weeks.

“I will approach the Education Council meeting seeking to get agreement on schools funding because it’s important to every family in Australia,” Mr Tehan said.

Independent and Catholic school authorities, which receive funding directly from the federal government for their schools, are inching closer to securing their own  deal.

But the Victorian government needs to negotiate a separate agreement with Canberra for additional funding for state schools.

Australian Education Union deputy Victorian president Justin Mullaly said the uncertainty was making it difficult for schools to plan for next year.

State schools will receive their indicative budgets for 2019 this month, but they won't include any additional money earmarked in the Gonski 2.0 plan until a new agreement is reached. That may not happen until December.

“We are talking about an environment where investment in new programs is up in the air,” Mr Mullaly said.

“Principals are really clear, they want to know what contribution the federal government will make to boosting their school budgets.”

Grattan Institute school expert Peter Goss said schools needed funding certainty now.

"We are less than four months out from the state of the new school year. People are making hiring decisions right now," he said.

Dr Goss has repeatedly warned the federal government against striking any “special deals” with the non-government sector.

“If the government ends up doing a special deal that favours one group of stakeholders, every stakeholder will turn around and want their own,” he said.

“That’s a terrible way to make public policy.”

Independent Schools Victoria chief executive Michelle Green said the independent schools sector was working with Mr Tehan to achieve a "fair and reasonable resolution".

"An immediate priority is ending the uncertainty over funding for 2019," she said.

"At the same time we are also focussed on the complex details of implementing a long-term and enduring funding model that is sector-blind and based on the needs of students."

In April, Mr Merlino promised to significantly boost Victoria's contribution towards the Schools Resourcing Standard, the bedrock of the Gonski review into school funding.

This would result in Victoria shelling out an extra $10 billion to state schools over the next decade.

This would lift Victoria’s contribution from 66 per cent, the lowest share in Australia, to 75 per cent, as set out in federal legislation.

The federal government has said its Gonski 2.0 model will inject an extra $25.3 billion of federal funding into Australian schools over the next decade.

The Catholic sector has waged a vocal campaign against the federal government's Gonski 2.0 proposal, saying it will unfairly penalise Catholic schools. It has been particularly critical of the socio-economic status model currently used to determine funding.

The government is considering recommendations of the National School Resourcing Board, including assessing the socioeconomic status of non-government schools based on the income tax paid by their families.