Unis 'weighed down' by costs: minister

Australia's university system is being "weighed down" by mounting costs to government and unpaid debts, the education minister says.

Tuesday's budget will reveal changes to university funding but Simon Birmingham has told ABC radio they will be different to the unpopular deregulation plan outlined in 2014.

It's been reported the government is looking at softening the blow by limiting the size of fees universities can charge students.