Union members clashed with University of Sussex management today over claims the university had censored anti-outsourcing protests.
The university has seen vigorous protests from staff and students over plans to privatise 235 non-teaching positions - around a 10th of its workforce.
Sussex's statutes include "the right of any member of staff to express political, religious, social and professional views - both privately and in public - provided it is within the law."
But the University and College Union said today it had received reports the university's council members had been ordered "not to engage" with trade unions.
Meanwhile union rep Rob French had been banned from using campaign materials in his signatures on the university's email system and a staff member facing outsourcing had reportedly been told to take off a "1/235" lapel badge.
Regional officer Michael Moran said he did not want to see "any attempt to close down debate. Understandably, staff employed by the university want to remain employed by the institution.
"History tells us that private firms cut pay and benefits in their drive to make money, which results in a bad deal for the staff and a bad deal for those who use their services."
A University of Sussex spokeswoman declined to say specifically whether badges, posters and other imagery were protected forms of expression.
But the university had "a very clear commitment to freedom of speech" enshrined in the university statute.
The allegations came a week after hundreds of demonstrators marched through the Brighton campus, seizing control of the Michael Chowen lecture theatre.