Universities should limit the number of pupils they offer places to from private schools.
This is according to Liberal Democrat deputy leader Simon Hughes, who suggested that universities are failing to reflect society.
Speaking to the Guardian, he said: "I think my message to the universities is: You have gained quite a lot in the settlement. Yes, you've lost lots of state money, but you've got another revenue stream that's going to protect you. You now have to deliver in turn. You cannot expect to go on as you are. It has failed miserably."
Universities that plan to charge more than £6,000 a year from 2012 should ensure they improve access, Mr Hughes commented.
Almost half of students at Oxford were educated at private schools.
In related news, it was revealed last week that the Open University is attracting younger students than ever, as people take on part time study in a bid to avoid debt.