Brown University in Providence, R.I. (Ruby Wallau for The Washington Post)

The National Labor Relations Board is set to revisit a 2016 ruling that granted teaching and research assistants at private universities legal protection to form unions, a move that could disrupt collective bargaining at some of the nation’s elite schools.

According to a document released this week, the board expects to issue a rule in September clarifying whether the “services” that graduate students perform for universities should be considered work. The labor board did not immediately respond to requests for comment on the rulemaking.

The labor board has a history of shifting positions on the question of graduate worker rights that reflects the ideology of the party in power. The board supported collective bargaining for graduate students at New York University in 2000, but four years later, with members appointed by President George W. Bush, it reversed the ruling in a case involving Brown University. That decision was then overturned in 2016 by a board largely appointed by President Barack Obama.

“We are disappointed in the Trump Labor Board’s willingness to call into question our labor rights and the progress we have made,” said Jess Issacharoff, a doctoral candidate in literature at Duke University. “Continuing attacks on our rights as workers will only force us to escalate otherwise easily resolved issues to protests, occupations and strikes.”

Many in the graduate student labor movement anticipated the 2016 ruling would be overturned as Republicans took control of the labor board. President Trump named Philip A. Miscimarra, who was the only dissenter in the 2016 graduate ruling, chairman and nominated lawyers Marvin E. Kaplan and William J. Emanuel to fill two of five seats on the NLRB.

After Kaplan and Emanuel were confirmed, labor organizers prepared for the worst.

Union organizers at Duke accelerated their campaign to join the Service Employees International Union. The university challenged the eligibility of more than 500 ballots, but a preliminary tally was decidedly against unionization.

Rather than become mired in litigation, Duke students withdrew their petition and formed a union without formal legal recognition or collective bargaining rights. SEIU suspects this approach will become more popular among graduate workers if the labor board shuts down the legal route to a union.

Teaching and research assistants could also follow the path of graduate students at Georgetown and Brown universities who successfully petitioned their schools for voluntary recognition of their unions.

Voluntary agreements spare students from the potential of the labor board changing position on students’ legal protection as employees, and universities can avoid litigation that tends to arise over the scope of the bargaining unit or other disputes. Still, many schools remain reluctant.

Administrators at Boston College and the University of Chicago have refused to recognize graduate student unions, despite pleas from organizers who withdrew petitions with the labor board and instead sought voluntary agreements. University leadership insists that students are not employees.

Other top universities made the same argument when teaching and research assistants at Columbia University filed a petition with the NLRB to join the United Auto Workers and challenged the Brown ruling. At the time, the Massachusetts of Institute of Technology, Stanford University and the entire Ivy League submitted a brief that said bringing students to the table would disrupt operations if negotiations included class length, amount of grading or what is included in curriculum.

Graduate students say collective bargaining is the only way universities will listen to their demands for balanced workloads, higher pay and comprehensive health insurance.

“Anyone who’s spent any time on a college campus knows that grads are workers as well as students — they grade the papers, teach the classes and do the research that knits their institutions together,” said Randi Weingarten, president of the American Federation of Teachers, the nation’s second-largest educators union. “Grads’ legal status was settled conclusively in Columbia and for the board to revisit it now, without a case before it, shows just how desperate it is to attack the right of workers to join a union.”