The Association of University Teachers has threatened to take legal action against Brunel University if it tries to make some long-serving members of staff redundant.
The union and the university are in a bitter dispute over the plans to boost Brunel's research standing by axeing 60 "research-inactive" staff. Up to half the redundancies will be compulsory.
AUT lawyers have written to the university telling it that staff appointed before November 20, 1987, and not subsequently promoted, are protected against compulsory redundancy.
So far, four members of staff in this position have volunteered to be named in the injunction.
The university council was meeting to discuss the cuts package as The Times Higher went to press. If the council endorses redundancies against this group of staff, the AUT said it would seek an injunction against Brunel.
The AUT is balloting Brunel members over industrial action against the planned job cuts - the ballot deadline is April 1.
The university declined to comment until after the council meeting.