An Oxford college head has hit back at claims Oxbridge does not do enough to attract more state school students.
Oxford's dreaming spires can seem impermeable to some students
Warden of New College, Professor Alan Ryan, said Oxford and Cambridge would miss their target of attracting 62% of applicants from state schools by 2012.
It was not because Oxbridge did not seek out "just about every plausible" state and private pupil, he said.
It was more that rich parents could buy the educational advantage that led their children to get the right grades.
This meant that more independent school than state school pupils were getting the necessary three grade As at A-level that made them potential Oxford or Cambridge material .
Prof Ryan's comments come after Universities Secretary John Denham warned of social bias against working class pupils in the higher education system.
They also follow a report by the Institute for Public Policy Research calling on Oxbridge to do more to attract students from state schools.
Writing in the Times Higher Educational Supplement, Prof Ryan said Oxford and Cambridge would never be able to hit their targets unless the proportion of state school pupils who got higher grades increased.
"Both spend a great deal of money sending out ambassadors to persuade more state schools to send applicants; both spend a lot of time and money on summer schools," he said.
He continued: "So what is the bias in the system? It is simple. It is called money.
"It purchases advantage for your children, from antenatal health through to quality of early years social interaction and ending with a choice of schooling."
He points out that in the US, test scores correlate with parental income.
And he adds that if Oxbridge took undergraduates on the basis of results alone, then its "social class profile would be more skewed than at present".
In 2006, some 42% of Oxford applicants came from state schools. This compares to the 54% of Oxford undergraduates that came from state schools.
The article appeared as Higher Education Minister Bill Rammell said a programme to encourage more pupils from working class backgrounds to apply to university would continue until 2011.
Aimhigher allows students from deprived neighbourhoods and schools with limited records of sending pupils on to university to visit college campuses.
"University education is an instrument of social change, perhaps the most powerful one at our disposal," Mr Rammell said.
Director of undergraduate admissions at Oxford Mike Nicholson said: "Oxford strives to ensure that we recruit the most able students, regardless of their background.
"We cannot address inequalities in the school system alone, but we work closely with schools and work very hard towards raising aspirations and attainment among school students."
He added that Oxford's widening participation and schools liaison team supported 700 school visits last year, reaching 20,000 students.