The Transport and General Workers union has accused universities of paying "poverty wages" to the "forgotten army" of cleaners, porters, catering, security, gardening and clerical staff.
General secretary Bill Morris has called on the government to significantly increase investment in higher education in the forthcoming comprehensive spending review to end the "scandal".
Mr Morris said that while vice-chancellors earned "fat-cat" salaries, the majority of catering and cleaning workers in old universities are paid Pounds 4.06 an hour, barely above the minimum wage.