Termination of schools funding under the Gonski model after four years will deliver an ''overpayment'' of $169 million a year to 163 wealthy independent schools in NSW, analysis shows.
The NSW Greens claim the Abbott government's decision to axe the final two years of the six-year funding deal struck by the Gillard government means the average public school will lose $357,000 a year by 2020.
The analysis suggests schools including Loreto Kirribilli, Brigidine in St Ives and St Aloysius in Milsons Point will be paid more than $5 million a year extra after the agreement lapses in 2018.
Under the Gonski agreement, the private schools were to retain existing funding while more disadvantaged schools, independent and public, were to receive increased funding on a needs basis.
The axing of the model means the expected increase in funding for disadvantaged schools will stall in 2018 and 2019, while the wealthy private schools' money will be maintained at current levels.
''The state's 163 wealthiest private schools will continue to be paid $169 million a year more than the Gonski amount,'' Greens MP John Kaye said. ''More than $68 million a year of that overpayment goes back to John Howard's funding maintenance deal with the powerful private school lobby.''
A spokesman for the NSW Department of Education said schools across all education sectors would lose $1.2 billion as a result of the federal government's abandonment of the final two years of the Gonski agreement.
Australian Education Union president Angelo Gavrielatos said the calculations highlighted the need for the full six-year implementation of the Gonski funding ''without which the resource gaps and achievement gaps will grow''.
''By not committing to the full six-year implementation of Gonski, the Abbott government is effectively turning its back on our most needy students and entrenching disadvantage,'' he said.
Trevor Cobbold, the convener of Save Our Schools and a former Australian Productivity Commission economist, said Education Minister Christopher Pyne's declaration last month that his government had an ''emotional commitment'' to private schools ''serves to perpetuate disadvantage in education''.
A spokesman for Mr Pyne said the Greens modelling was wrong. ''All schools currently have their Commonwealth funding calculated based on the new funding model and this will continue,'' he said. ''From 2018 Commonwealth funding for both government and non-government schools will be indexed at CPI plus enrolments, and increase every year.''
Dr Kaye said: ''The minister is playing with words. The Australian Education Act makes it abundantly clear the new funding for each non-government school for 2014 to 2017 is based on what they received in 2013 and cannot be reduced.''