Swansea University's Association of University Teachers is set to take on the university's student union in an unprecedented employment dispute at an industrial tribunal next week.
The AUT will claim that the student union unfairly dismissed its member, student union manager Nick Tregonning, earlier this year.
Mr Tregonning was dismissed for alleged "incompetence". The AUT said the dismissal breached the student union's procedures and employment law.
The student union has offered to settle the matter with a significant sum of money and a public apology. But it has said that it will refuse any order to reinstate Mr Tregonning.