The university's admissions data confirms that only one black Briton of Caribbean descent was accepted for undergraduate study at Oxford last year.
Figures revealed in requests made under the Freedom of Information (FoI) Act by the Labour MP David Lammy also show that Oxford's social profile is 89% upper- and middle-class, while 87.6% of the Cambridge student body is drawn from the top three socioeconomic groups. The average for British universities is 64.5%, according to the admissions body Ucas.
The FoI data also shows that of more than 1,500 academic and lab staff at Cambridge, none are black. Thirty-four are of British Asian origin.
One Oxford college, Merton, has admitted no black students in five years – and just three in the last decade. Eleven Oxford colleges and 10 Cambridge colleges made no offers to black students for the academic year beginning autumn 2009.
Oxford's breakdown of its latest undergraduate admissions figures, published on its website, shows that just one black Caribbean student was accepted in 2009, out of 35 applications.
A total of 77 students of Indian descent were accepted, out of 466 applications. Six black Caribbean undergraduates were accepted at Cambridge the same year.
In advance of a crucial Commons vote on Thursday, ministers have said universities that want to charge students up to £9,000 a year in fees will face fresh targets on widening access to applicants from disadvantaged backgrounds. Oxford and Cambridge, which are expected to charge the maximum fee, say they are keen to recruit the brightest students from all backgrounds. Both have programmes to encourage applications from state school students, and those from black and working-class backgrounds.
But the FoI data shows white students were more likely to be successful than black applicants at every Cambridge college except St Catharine's, where black candidates have had a 38% success rate, compared with 30% for white students.
The starkest divide in Cambridge was at Newnham, an all-women's college, where black applicants had a 13% success rate compared with 67% for white students. The data for Oxford tells a similar story: at Jesus college white candidates were three and a half times more successful than black candidates over an 11-year period. Oxford says the figures are too low for the variation between colleges to be statistically significant.
The most selective universities argue that poor attainment at school level narrows the pool from which candidates can be drawn. But black candidates are more likely to apply to elite universities.
In 2009, more than 29,000 white students got three As or better at A-level (excluding general studies) and about 28.4% applied to Oxford; while 452 black students got three As or better, and nearly half applied to Oxford. A spokeswoman for Oxford said: "Black students apply disproportionately for the most oversubscribed subjects, contributing to a lower than average success rate for the group as a whole: 44% of all black applicants apply for Oxford's three most oversubscribed subjects, compared with just 17% of all white applicants. That means nearly half of black applicants are applying for the same three subjects … the three toughest subjects to get places in. Those subjects are economics and management, medicine, and maths.with 7% of white applicants. This goes a very long way towards explaining the group's overall lower success rate."
The FoI figures show large parts of the country never send students to the most prestigious universities. No one from Knowsley, Sandwell and Merthyr Tydfil has got to Cambridge in seven years. In the last five years, pupils from Richmond upon Thames have received almost the same number of offers from Oxford as the whole of Scotland.
Rob Berkeley, director of the Runnymede Trust, a thinktank that promotes racial equality, said: "If we go for this elite system of higher education … we have got to make sure what they are doing is fair. If you look at how many people on both frontbenches are Oxbridge-educated, Oxford and Cambridge are still the major route to positions of influence. If that's the case we shouldn't be restricting these opportunities to people from minority backgrounds."
Black students do not lack aspiration, but the opportunity to get into the most prestigious universities, Berkeley argued. "Of the black Caribbean students getting straight As at A-level, the vast majority apply to Oxbridge.... those who do choose to apply have a much lower success rate [than white applicants]. One in five in comparison with one in three for white students. That doesn't seem to have shifted for the last 15 years." A boom in university participation in recent years has led to a more diverse student body, but black students are concentrated in a handful of institutions. In 2007-08 the University of East London had half as many black students as the entire Russell group of 20 universities, which include Oxford and Cambridge.
Matthew Benjamin, 28, who studied geography at Jesus College, Oxford, said: "I was very aware that I was the only black student in my year at my college. I was never made to feel out of place, but it was certainly something I was conscious of.
"When I arrived and they wanted to do a prospectus, and have some students on the cover, they chose me, and one other Asian guy and another guy from Thailand. It was clear they wanted to project this image of somewhere that was quite diverse. The reality was very different – there were three [minority] ethnic students in a year.
"On open days, some black kids would see me and say 'you're the only black person we've seen here – is it even worth us applying?'"
A spokesman for Cambridge said 15% of students accepted last year were from minority ethnic backgrounds. "Over the five years to 2009 entry black students accounted for 1.5% of admissions to Cambridge, compared with 1.2% of degree applicants nationally who secure AAA at A-level. Colleges make offers to the best and brightest students regardless of their background, and where variations exist this is due to supply of applications and demand by subject."