The territory's non-government sector is the only in the nation to definitively lose out under a policy proposed by Prime Minister Malcolm Turnbull and Education Minister Simon Birmingham on Tuesday.

Mr Turnbull declared he would "bring the school funding wars to an end" in a stunning policy turnaround that will see the federal government pump an extra $19 billion into schools over the next decade.

At a surprise press conference flanked by businessman David Gonski, who conducted a landmark review of school funding for the Gillard government, Mr Turnbull said he would succeed where Labor failed by delivering a genuine needs-based funding model.

Mr Gonski will conduct a new review for the government - dubbed "Gonski 2.0" by Mr Turnbull - on how the extra money can best be spent to ensure it boosts student performance and school results.

Next Tuesday's budget will include an extra $2.2 billion extra for schools over the next four years on top of the $1.2 billion announced in last year's budget.

Funding for public schools will grow by 94 per cent, or $6.4 billion, over the decade while Catholic and private school funding will rise by 62 per cent or $6.7 billion.

The government's own briefing documents state the government is still spending $22 billion less over a decade than Labor promised schools at the last election.

Although funding is growing strongly overall, the new policy will involve a substantial shuffling of funds between the states and different school sectors.

All schools will now reach their appropriate funding level within a decade, according to the government.

"This investment will set Australian children on the path to academic excellence and success in their future lives," Mr Turnbull said.

"It will deliver real needs-based funding for children from all backgrounds in every town and every city and every region and every state - in every classroom of our great nation.

"This reform will finally deliver on David Gonski's vision six years ago after his landmark review of Australian school education."

Education Minister Simon Birmingham said 24 schools in the nation's highest socioeconomic areas will see their funding drop next year. This represents a break from Julia Gillard's promise that no school would lose a dollar under any funding changes.

Figures previously provided by the federal Department of Education indicate nine ACT schools received more than 100 per cent of total public funding according to the current school resourcing standard:

Senator Birmingham said the announcement would end the "Twenty-seven different school funding agreements that our government inherited that were largely based on ancient sweetheart deals".

Catholic Education Office Archdiocese of Canberra and Goulburn director Ross Fox met with Senator Birmingham on Tuesday afternoon and came out swinging against what he labelled a funding freeze.

Under a special deal struck by the former Labor government, the ACT's Catholic schools were funded according to an allocated socioeconomic score of 101 despite many measuring above that.

Under the new policy it is understood this deal will be scrapped, with funds provided to all Catholic and independent schools in Canberra to be reduced over the next decade.

"The reality is that census measures don't identify disadvantage in the ACT well," Mr Fox said.

"We're at the lowest relative level of government funding compared to government schools, and this Commonwealth government thinks we should go even further backwards."

ACT Education Minister Yvette Berry acknowledged the proposed reduction in funding for non-government schools.

"The federal minister has indicated that these schools will be supported by the Commonwealth with transitional funding," she said.

"Again we're working through the detail and my office and directorate have spoken to the peak bodies for both the Catholic and independent schools."

Senator Birmingham said states would also be required to at least maintain their real per student funding levels or face a reduction in Commonwealth funding.

According to the Productivity Commission, the ACT government cut school funding by 4.8 per cent between 2010 and 2015 while the Commonwealth's contribution rose 17.1 per cent.