A group of New York University graduate students resume their strike today, meaning another semester of uncertainty for some undergraduates who have seen classes cancelled or moved off-campus by supporters of the strike.

With the support of top union leaders across the country and local political allies, including the newly appointed City Council speaker, Christine Quinn, the unit chairman of the Graduate Student Organizing Committee of United Auto Workers local 2110, Michael Palm, said he is as confident as ever that the union will prevail at NYU.

“People are determined to stay out on strike for another semester,” Mr. Palm, a Ph.D. candidate in the American studies program, said.

About 1,000 graduate students work at NYU as professors, graders, and assistants. Several hundred began their strike November 9, a little more than two months after their unprecedented union contract expired on August 31.The university opted not to renew the contract after a National Labor Review Board decision overturned graduate assistants’ right to bargain as a union in July 2004. Following months of deliberations last summer, including meetings with professors and union leaders, administrators made the decision to make a take-it-or-leave-it offer to represent graduate assistants without a third-party grievance procedure or mandatory membership, but union leaders rejected the offer, leading to a strike.

Large numbers of faculty and students have come forward in supporting the union, but a swath of animosity also emerged last semester. Students living in a dormitory near Bobst Library publicly admonished the union for waking them up with their whistling, chaotic drumming, and chanting starting at 8 a.m. every morning of the school week.

Prominent professors, including the chairman of the philosophy department, Paul Boghossian, have publicly defended the university’s decision not to recognize the union for a second contract.

Some professors have taken a militant stance against administrators, claiming the university compromised the traditions of faculty governance and academic freedom, forcing them to take drastic measures.

One such professor, Andrew Ross, the chairman of the American studies program and a founding member of Faculty Democracy, a group advocating for increased faculty participation in the running of the university, went as far as withholding students’ grades until the dispute is resolved. He said he thought others were doing the same.

The latest tactic to pressure the university into negotiating a second contract may involve an investigation by the American Association of University Professors, an organization dedicated to defending academic freedom and promoting shared governance at universities. It could choose to add the university to its “censured” list.

The organization’s general secretary, Robert Bowen, said via e-mail that they are still deciding whether to send an investigatory commission to NYU. He said a former university president and a prominent New York attorney have agreed to join the committee, but he didn’t give their names.

The university has continued paying the striking graduates students, despite an ultimatum issued in December by the university president, John Sexton, that graduate students who continue to refuse to teach their classes would lose their teaching positions and their stipends for the spring semester. A university spokesman, John Beckman, said that if some graduate assistants continue to strike in the coming weeks, they will be subject to such penalties. They will, however, continue to receive full tuition remission and health benefits because their fellowships are considered scholarships, he said.

A student council committee and several professors have tried to broker a proposal that would mandate a union like organization within the university that would not involve the UAW. So far, those attempts have been to no avail.

One graduate student said both sides of the dispute have contributed to the polarization on campus.

“Both sides seem to be overstating the case,” a joint law and philosophy Ph.D. candidate, Alex Guerrero, said. “The rhetoric has remained at a very high pitch. I don’t see a lot of progress. It’s not good for building community.”