Harvard University and more than 4,000 graduate student workers failed to reach agreement on a labor contract during negotiations Monday, setting the stage for an indefinite strike to begin Tuesday at 10:30 a.m.

The strike could complicate the completion of academic work done at the semester's end, from grant applications to pre-exam reviews, final grading and more.

“Research assistants won’t do their research,” said Rachel Sandalow-Ash, a member of the bargaining committee for the Harvard Graduate Student Union (HGSU). “On the teaching side, student-workers will not hold review sessions and will not grade exams.”

In a statement, university spokesman Jonathan Swain called the strike "unwarranted," saying it "will neither clarify our respective positions nor will it resolve areas of disagreement."

HGSU members plan to picket outside academic buildings, asking other members of academic staff -- including tenured and adjunct faculty -- not to take on work formally assigned to graduate students.

After years of organizing, HGSU formed in April of 2018. The union covers the work of graduate students — and a smaller cohort of undergraduates — who together perform thousands of hours of research, teaching and administrative duties at Harvard each week.

For its part, the university has shared online resources for faculty concerned about the strike's effect on teaching and learning, including a page of "frequently asked questions."

Harvard and HGSU began negotiating their first contract in October of last year, but the two sides have long been stuck on a number of core provisions.

Union negotiators allege that the university is declining to implement a fair raise and pay stability for student-workers who tend to live with fast-rising rents in Cambridge, Somerville and other parts of greater Boston.

As a nonsalaried research assistant at Harvard Law, Sandalow-Ash (for example) is paid $12 an hour — the minimum hourly wage in Massachusetts. She said that the university signaled an intention to raise minimum hourly pay for students in nonsalaried roles to $15, which will be the state's mandatory minimum wage by 2023.

Sandalow-Ash argued that Harvard, with its world-leading $40-plus billion endowment, "can do way better than minimum wage.”

The university has also proposed 5 to 8% raises for unit members across the three years of the contract. On its website regarding the negotiations, university officials described that proposal as "in line with the wage increases found in existing contracts" between other universities negotiating with graduate students.

Benefits are another sticking point. The university has so far declined to provide graduate students with more than optional dental insurance, or adequate access to medical specialists or mental health resources. Harvard has said that would end up affecting health care for students not covered by the contract. The university also proposed a $100,000 fund for grants to defray the costs of premiums and co-pays for dental health.

But the union's most prominent demand is to let graduate students submit grievances — ultimately subject to third-party arbitration — regarding cases of alleged harassment or discrimination. Sandalow-Ash observed that members of Harvard's other unionized workforces — including clerical and dining-hall workers — can "grieve" those problems under their own existing contracts.

In response, university officials have said that such a system would create a separate process of adjudication available to some but not all students, and might involve cross-examinations in cases of alleged misconduct.

Union leaders pointed to a recent survey of more than 8,000 of undergraduate and graduate students, only 46.5% expected the university to conduct a "fair investigation" after an instance of sexual misconduct was reported.

Last year, some graduate students criticized Harvard administrators for failing to discipline Jorge Dominguez, a prominent professor of government and vice-provost accused of sexually harassing women — often junior colleagues or graduate students — over the course of decades.

This spring, the university stripped Domínguez of his emeritus status and launched an internal review of its handling of "reports or allegations of misconduct."