Oxbridge receives millions of pounds of extra government cash for their students through support for special fees charged by colleges. This yields up to pounds 2,000 more for each student than other universities receive.
With acute pressure on spending because of the expansion in the number of students, ministers are reviewing that financial privilege.
Numbers are increasing more rapidly at newer universities, making Oxford and Cambridge's claim on extra funding weaker, they say. The number of students going on to higher education has increased by 46 per cent over four years.
The review is the latest in a series of attempts by Michael Portillo, Chief Secretary to the Treasury, to restrain costs in higher education. College fees have come under scrutiny because the Government pays them only to a small number of institutions which operate a collegiate system - mainly Oxbridge - on top of the usual tuition fees which all universities receive.
Abolition of college fees is an option under consideration by the Department of Education, although that outcome is unlikely. Stripped of all the subsidy, Oxbridge would probably pass on extra charges direct to students, thereby encouraging an elite core of other universities to do the same.
At present, the Government subsidises college fees with about an extra pounds 2,800 for each of Oxbridge's 20,000 domestic students. Some of this extra money is clawed back through another system by the Higher Education Funding Council for England.
The most likely outcome of the review is that the subsidy formula will change, allowing HEFCE to take back another pounds 10m a year. Another possibility is a change in the way the college fee money is distributed within the universities. The Department would monitor more carefully how the money was spent by each college.