Academic freedom could be undermined by the government's counter-terrorism plans, say university chiefs.
Universities issued guidelines warning against "intimidation"
The Terrorism Bill could obstruct the teaching of science and the sharing of information by librarians, the president of Universities UK has said.
Professor Drummond Bone said, for example, chemists may be banned from producing certain substances.
Higher Education Minister Bill Rammell rejected the comments, saying: "I do not think those fears are justified."
The warning from academics about the risk of unintended consequences of the anti-terror measures was given as universities presented their own plans to tackle fears over campus extremism and intolerance.
"Universities UK has grave concerns that certain elements of the Terrorism Bill might cut across academic freedoms," said Professor Bone.
The terror plans were "loosely drafted", warned Professor Bone, in a way that could interfere with legitimate university activity.
"One gets worried when chemists might be forbidden from producing a certain kind of noxious substance. Where do you draw the line there?
"Librarians are worried about lending material which might be construed as having details about terrorism."
He also questioned whether the academic study of the Middle East could be interpreted as the "encouragement" or "glorification" of terrorism.
But Mr Rammell said academics had no reason to be concerned.
"The key proposal is the intention of the person who acts or by their statements seems to incite others to commit acts of terrorism," said Mr Rammell.
"I don't think within that context that there is anything legitimate academic freedom has to fear."
Professor Bone was speaking at Universities UK's launch of guidelines to tackle "hate crimes" and intolerance on campuses - following fears that there had been a growth in political or religious extremism among students.
The guidelines from the higher education organisation assert the right of students and staff to "work, study and live without fear of intimidation, harassment and threatening or violence behaviour".
Universities UK says its publication, Promoting Good Campus Relations: Dealing With Hate Crimes and Intolerance, has rejected a "one size fits all" approach to setting rules on protecting "free debate and the interchange of ideas".
The report considered a range of areas of extremism and intolerance, including race, religion, homophobia, animal rights, disability and party politics.
In September, Mr Rammell had said he was "extremely worried" by a survey of Muslim students showing one in 10 would not immediately warn the police of a terror attack.
Presenting the survey, the Federation of Student Islamic Societies, argued that reports of extremism among Muslim students had been "grossly exaggerated".
Education Secretary Ruth Kelly has also urged universities to maintain the balance between protecting free speech and guarding against "unacceptable behaviour" by students or staff.
Speaking in September, against a background of reports of campus extremism, she said: "That means informing the police where criminal offences are being perpetrated or where there may be concerns about possible criminal acts."
Professor Anthony Glees, of Brunel University, had warned a range of extremist groups were operating in universities and recruiting among the students.
These groups included Islamist Jihadists, animal rights activists and the British National Party, said Professor Glees.