Eastern Michigan University has warned striking professors that walkouts by public employees are illegal under Michigan law, and has said that it will suspend further negotiations with the faculty union if the three-day-old strike does not end by 10 p.m. Tuesday. Classes are scheduled to begin on Wednesday.

In a written statement issued by the university on Sunday night, the institution’s president, John A. Fallon, called on the faculty union to put the interest of students first.

Howard Bunsis, president of the local chapter of the American Association of University Professors, told The Ann Arbor News that union members were disappointed with the administration’s ultimatum. “This is not the time to threaten to walk away,” he said. “This is the time to talk about doing whatever it takes to get students to class on Wednesday.”

The union represents 689 professors, whose contract with the university expired on August 21. Mediation is scheduled to resume this evening.