Businessman David Gonski, who led a panel on education funding, said in the past decade Australia's top students had continued to fall behind relative to international standards.

``The direction which we're going is not good,'' Mr Gonski told a forum of disability advocates in Sydney.

``The division between the top and the bottom of our students is getting more marked.''

Mr Gonski declined to comment on whether he believed the federal government would help achieve his proposal for Australian governments to commit an extra $5.4 billion a year to lift student performance.

``I don't think it's for me to judge that,'' he said.

Earlier, he told the forum that $5 billion was a relatively small amount of money.

``I accept that $5 billion is not for the faint-hearted, it's a big number but let's put it in context,'' Mr Gonski said.

``It is just under 15 per cent of the money spent on education in 2009; it is also less than half of 1 per cent of the GDP of Australia.''

Parliamentary secretary for school education Jacinta Collins said the extra school funding was contingent on state and territory governments.

``The Commonwealth isn't in a position to make any specific commitment until we have the discussions and negotiations with states and territories,'' Senator Collins said.

Mr Gonski defended the use of 2009 National Assessment Program Literacy and Numeracy data to analyse student performance and propose a model to increase school funding.

It found that only 16 per cent of all schools met the national minimum standards for literacy and numeracy.