The London School of Economics operates a quota for state school pupils, it was revealed this week, fuelling fears among the independent school sector of admissions bias at top UK universities.
Confidential advice for admissions tutors, obtained by The Times Higher under the Freedom of Information Act, shows that the LSE sets aside 40 places a year for pupils from poorly performing state schools.
The document states: "These notes should not under any circumstances be discussed with any member of the public, including students, parents and schools."
Every English university has set its own "milestone" against which it will measure progress in widening participation. These milestones are included in the access agreements submitted to the Office for Fair Access. Offa is due to publish access agreements next week.
Despite earlier independent school claims that universities such as Bristol were biased in favour of state school students, the LSE is the first to be shown to operate a quota system.
Cath Baldwin, head of recruitment and admissions at the LSE, said the discretionary places scheme had been introduced because applicants from independent schools were more likely to be offered a place than those from state schools.
She said: "It's difficult to see this as discrimination given the number of places given to students from independent schools.
"Independent school students have traditionally done better at securing places, and 40 places represent just 6 per cent of our home and European Union intake.
"The discretionary places scheme does not apply to a vast range of state schools - those that perform above the national average in terms of GCSE grades - so LSE does not regard this scheme as a state versus independent school issue."
But the Headmasters' and Headmistresses' Conference, which represents the heads of leading independent schools, condemned the practice.
Philip Evans, chair of the HMC subcommittee on university admissions and headmaster of Bedford School, said that the policy contravened Steven Schwartz's recommendations on fair access.
He said: "This is a policy of which we were unaware and which gives rise to significant concern.
"It is wholly at variance with the accepted principle that any selection process should be transparent, and the preamble to the document makes it clear that it was essentially secret."
In his first speech as Higher Education Minister, Kim Howells stressed that the Government had no official targets or quotas. He said: "We do not have any admissions targets."
The access agreements will cover every English university that wishes to charge more than £1,200 a year in tuition fees for home undergraduates. They will include the level of fee to be charged and plans for bursary support.
Just two universities - Leeds Metropolitan and Thames Valley - plan to charge less than the maximum £3,000 a year for a degree course.
Leeds Met will charge £2,000 a year and Thames Valley £2,700 a year across the board.