David Willetts is having a torrid week. Just a day after the Prime Minister was forced to intervene to defuse a row of the Universities minister's making, Mr Willetts seems to have done it again.

On Tuesday two newspapers ran stories on government plans to allow rich students to "buy" extra places at top-performing universities at the higher rates paid by foreign students. Mr Willetts went on the radio and declined to dampen the speculation. Cue fury from the Liberal Democrats for whom the tuition fees furore is already the most poisoned of chalices. By lunchtime David Cameron had to step in, insisting this was not what the Government intended at all.

Mr Willetts's latest suggestion that some universities might reduce the amount they charge to students at clearing might – on the surface – be regarded as a good thing. Those universities which had set their course fees too high would reduce them to the benefit of students.

But look more carefully and the problems emerge. Parents and prospective students just want to know how much a degree is going to cost – but have been left floundering by a lack of information.

And, as the Office for Fair Access points out, discounting fees late in the application cycle is unfair to applicants who chose not to apply to a course on the basis of the fee advertised earlier.

The access watchdog is also concerned that last-minute discounts will encourage applicants to apply late in the hope of paying less – reducing their chances of being admitted.

Such risks, they point out, are more likely to be taken by applicants from disadvantaged backgrounds, concerned by taking on large debts.