Union negotiators for striking dining hall workers and Harvard administrators have reached a tentative agreement on a new contract, a spokeswoman for the university said Tuesday.

If approved by workers, the new contract will end a strike that spanned nearly three weeks. The labor dispute prompted a student walkout in support of the workers and criticism of the university's position by Boston City Council members.

The Harvard Crimson reported that negotiations ended after 1 a.m. Tuesday, though the talks were scheduled to end at 5 p.m. on Monday. 

The university and Unite Here Local 26 reached an agreement in principle for a new five-year contract that "represents a fair and reasonable resolution to negotiations," said Harvard Vice President Katie Lapp. Local 26 has been in negotiations with the university since May. 

The tentative agreement came in the wake of a walkout by 600 Harvard students in support of the dining hall workers, who have been on strike since Oct. 5. About 750 workers were striking for annual earnings of at least $35,000 and a restructuring of their health insurance so that cost increases were not passed on to them. 

Students walked out of their classes at 2 p.m. on Monday to show solidarity with the dining employees and their strike — the first at the country's oldest university in more than 30 years. 

The agreement, which both Lapp and Local 26 President Brian Lang say address the main issues of wages and health care, will be presented by Local 26 to its members for approval. 

"Our strike will continue until all members on strike have a chance to review the agreement and vote to ratify," Lang said. "We will disclose details of the agreement after this vote on Wednesday.”

Lapp in a statement thanked independent mediators of the negotiations and the dining services workers for their patience and engagement. 

"The university has been unequivocal in its belief that dining services workers are valued employees and vital members of the Harvard community," she said. "We look forward to welcoming them back to work as soon as possible."

Students who walked out of class in support of the workers then marched on Monday to 124 Mount Auburn St., where the school was negotiating with dining hall workers.

“I support our HUDS workers because they go above and beyond for me,” Itzel Vasquez-Rodriguez, a senior at Harvard, said in a news release from the Harvard Student Labor Action Movement. “They make sure I’m healthy and I want to do the same for them. The dining hall workers are not fighting for themselves. They’re fighting for their families, they’re fighting for their children, they’re fighting so that they can come to work and serve us, the students.”

Some students stayed there until the end of negotiations and burst into chants and cheers when the tentative agreement was announced.