Britain's elite universities disagree over whether to use the new A* grade at A-level when making decisions about admissions.
Oxford University said it would not take the A* grade into consideration for at least two years, but Cambridge said it planned to make it a condition of entry from next summer. The grade will be available to pupils who take their A-levels from next summer.
"A lot of teachers said very clearly 'this is a new qualification that we haven't had a chance to teach'," Mike Nicholson, the Oxford director of undergraduate admissions, told the Headmasters' and Headmistresses' Conference. "They said 'the idea that we can accurately predict who will get it is difficult'."
The deadline for applying to Oxford and Cambridge for next year is 15 October. The universities have to make their offers based on predicted grades. Mr Nicholson said Oxford would review its decision in two years. However, Dr Geoff Parks, the Cambridge head of admissions, said that from 2010, candidates would be expected to get an A*-grade and two A-grade passes to gain entry to the university.
Meanwhile, a league table published today knocks Oxford out of the top two rankings of British universities. The Times Higher Education-QS table puts University College London ahead of it for the first time.