Be more open, universities are urged.
Vice-chancellors will have to include their admissions policies in the key agreements they sign with a Government watchdog in return for the right to charge top-up fees, Universities Secretary John Denham said.
Publicising the process for allocating places will help tackle fears that universities are guilty of "social engineering" by discriminating in favour of working class students, he said.
It will also answer critics who say particular universities are infected with "snobbery" because they admit so many students from privileged homes, Mr Denham added.
Speaking at Warwick University, the minister said universities needed to adopt "confidence building measures".
"On the one hand, universities that try to take a student's individual background into account are liable to be accused of political correctness and social engineering," he said. "On the other, there are plenty of people prepared to take the fact of a disproportionate number of students from more privileged backgrounds at a particular university as evidence of snobbery and social bias on the part of admissions staff.
"Ultimately the debate is corrosive of public confidence in the system."