In a discussion paper for the Oxford Centre for Higher Education Policy Studies, the academics also say that universities would be able to appeal against any penalties handed out by the Office for Fair Access.
The 2004 letter of guidance to Offa from Charles Clarke, the education secretary at the time, pointed out that the law puts universities' admissions policies and procedures outside Offa's remit. However, the guidance letter sent last month by Vince Cable, the business secretary, and David Willetts, the universities and science minister, tells a different story, the academics state.
Dennis Farrington and David Palfreyman, authors of The Law of Higher Education, argue that the ministers seem keen to influence admissions. They cite a 1957 US Supreme Court landmark case in which decisions about "who may be admitted to study" were deemed one of "the four essential freedoms of a university".
"It seems that the government really intends to try and influence, if not virtually dictate, university admissions policies," they write in a paper posted on the centre's website. "If this is indeed the case, it would perhaps be useful if the director of Offa speedily took expert legal advice concerning the 'guidance' he has just received.
"On the basis of that advice, he may be obliged to reject the guidance as being potentially an improper attempt to interfere with universities' academic freedom."
If Offa were to fail to fulfil its statutory duty of defending universities against "improper and illegal" interference in admissions, "perhaps the collective of...lay chairs of university councils/boards and the coterie of vice-chancellors will seek judicial review of Offa's neglect of duty", the paper suggests.
The authors argue that the letter "is, with respect, now so suspect" that it must be recalled, edited and reissued as guidance addressing only what is within Offa's legal remit.