A scholar of higher education has called on the academy to abandon "utopian views" of academic freedom and to adopt more realistic targets.
In an interview with Times Higher Education, Tim Birtwistle, visiting Fellow at the Oxford Centre for Higher Education Policy Studies, said it was a problem that "nobody can really define an acceptable definition of academic freedom".
He said he disagreed with the decision made by the campaign group Academics for Academic Freedom to omit from its own definition a reference to freedom "within the law", which is included in Section 202 of the Education Act 1988.
The AFAF states that it wants "academics, both inside and outside the classroom, (to) have unrestricted liberty to question and test received wisdom and to put forward controversial and unpopular opinions, whether or not these are deemed offensive".
Professor Birtwistle said he accepted that the phrase "within the law" was proving increasingly restrictive, citing the way in which anti-terror laws have impinged on scholars' work.
However, he said, it was futile to ignore it. "I can't see that those three words would ever be removed by any Parliament in this country."
The professor called on the Universities UK working group on academic freedom, which met for the first time in February, to press for Section 202 to be redrafted to define the full meaning of "within the law".
He added that stringent tests needed to be set up to ensure that future legislation would not have unforeseen deleterious consequences for academic freedom.
But Professor Birtwistle also attacked the view that academic freedom should give scholars the right to criticise the running of their own institutions.
"Some seem to think that academic freedom gives them that right," he said.
"But the fact is that if someone worked for a shop and said something condemning its management - not on the basis of whistle-blowing or one of those enshrined freedoms - they would get into hot water and expect to have a hard time at their place of employment. Academics should not be exempt from this."
He added that the University and College Union's statement on academic freedom, which links the concept to job security, was also a mistake.
"In this day and age, nobody is going to give absolute and wholehearted tenure to all academics," he said.
He urged the union to find "common ground" with the UUK working group, warning: "If we link a need for academic freedom to tenure, it's a lost argument; it just won't be won."
Professor Birtwistle, speaking in Birmingham last week after delivering a lecture on the topic organised by Martineau Education Sector Group, said he would define academic freedom as "the freedom to enquire, research and find things out, the freedom to say: 'Wow, we didn't know this', but not unfettered freedom to say anything about anything to anybody.
"I'm not sure our society wants that level of total freedom."