A group of academics is demanding the right to be controversial in a new campaign for freedom of speech.
Lecturers say their role is to question and test received wisdom
Academics for Academic Freedom (AFAF) says that in today's political climate it is "harder than ever" for scholars to defend open debate.
AFAF says they must be allowed to question received wisdom, and managers should not be able to discipline academics for voicing unpopular views.
The group is calling on all university lecturers to sign its online petition.
"Restrictive legislation, and the bureaucratic rules and regulations of government quangos and of universities themselves, have undermined academic freedom," the groups says.
"Many academics are fearful of upsetting managers and politicians by expressing controversial opinions.
"Afraid to challenge mainstream thought, many pursue self-censorship."
A Leeds University lecturer, Frank Ellis, took early retirement this year before a disciplinary hearing over his comments that there was evidence to suggest white people had higher IQ levels than black people.
Statement of freedom
The statement of academic freedom which lecturers are being asked to sign says two principles are the foundation of academic freedom:
"That academics, both inside and outside the classroom, have unrestricted liberty to question and test received wisdom and to put forward controversial and unpopular opinions, whether or not these are deemed offensive.
"That academic institutions have no right to curb the exercise of this freedom by members of their staff, or to use it as grounds for disciplinary action or dismissal."
Writing on the AFAF website, Professor Roy Harris from the University of Oxford said: "Getting university authorities to agree to these principles is an essential step towards safeguarding academic freedom for the future."
Professor Mary Evans from the University of Kent said: "Universities need to be able to maintain, and even extend their ability to think the unthinkable.
"They should not accept a role as mere instruments of state agendas."
Simon Davies, co-director of the policy engagement research group at the London School of Economics, added: "I'm deeply worried about the number of academics who flee in terror at the slightest wisp of controversy.
"Rather than engage the world in a spirit of challenge, too many academics have been sedated by an oppressive environment of political correctness and risk aversion."