The exam accounts for 60 per cent of successful applicants to Oxford, while the rest receive offers conditional on their A-level results.
Last night, the secretary of the colleges' admissions office, Jane Minto, said that she could not predict the outcome of Thursday's debate, which is the culmination of two years of discussions.
It had become increasingly difficult to set an exam which was fair to all candidates because changes to A-level courses meant that work which had been covered by some students had not been looked at by others, she said.
"Principally, people do still choose an entrance examination but we have found the number of applicants from both maintained and independent schools has increased for the conditional offer route."
It has been argued that the bias that Oxford still shows towards pupils from fee-paying schools could be eliminated by abolition of the exam.
However, this seems a less important factor than it would have been 10 years ago, when many independent school pupils took the exam in the term after A-levels while state school pupils tended to take it in the autumn of their upper-sixth year. Now both state and independent school pupils take it in the autumn term of their upper sixth year.
While state schools do still tend to favour the A-level route, some independent schools also prefer it. They say the examination is a distraction from A-level work.
Dr John Rowett, admissions secretary of Brasenose College, said the college would be voting against the move. With universities set to move to a post-A- level admissions system before the end of the decade, it would be premature to make any change at this stage.
"Any change we make must remain in place for some considerable time," Dr Rowett said. "It is disruptive to the schools if we have to make two changes very rapidly."Reuse content