An overwhelming majority of graduate teaching assistants affiliated with the Graduate Employees and Students Organization voted this afternoon to strike, promising to stop their teaching work for five days beginning Monday.

About 82 percent of graduate TAs in GESO voted in favor of the strike at the group’s membership meeting this afternoon, while 91 percent of non-teaching graduate students in GESO voted to support a strike effort, GESO chair Mary Reynolds GRD ’07 said. GESO leaders would not provide actual figures for the vote, which was conducted by secret ballot. Reynolds estimated that about 500 graduate students attended the meeting, which was closed to the press.

Only GESO members in the humanities and social sciences were included in the vote. Yale currently enrolls 1,124 doctoral students in the humanities and social sciences, according to University statistics.

Reynolds said she expects hundreds of graduate TAs to strike next week unless Yale President Richard Levin reverses the University’s long-standing position against graduate student unionization and agrees to recognize GESO as an official union.

“I would be happy to take a call from President Levin at any moment and sit down and negotiate,” Reynolds said at a press conference following the meeting at the First and Summerfield Methodist Church on College Street.

But Yale officials said the administration will not alter its stance and will not negotiate a contract with GESO. University spokeswoman Helaine Klasky said the administration is skeptical about the results of this afternoon’s vote.

“I would say given the fact that GESO refuses to release the numbers participating in the election, one can only assume it is not representative of the graduate students,” Klasky said. “By most estimates, only about a third of the graduates have ever supported GESO.”

At Columbia University, members of the Graduate Student Employees United, a group that has been working with GESO organizers to coordinate a joint strike action next week, announced this evening that 82 percent of its graduate TAs voted in favor of a strike this week.

Reynolds said she thinks the week-long strike will bring national attention to issues that concern graduate students, such as health care, pay equity and faculty diversity.

“This strike will actually put those issues in the national spotlight,” Reynolds said.

Although many graduate students leaving the meeting said they had voted for a work stoppage, Olga Bezhanova GRD ’09 said she voted against a strike.

“I think disrupting the academic program at this moment, during the last week of classes, is bad,” Bezhanova said. “But I really support all the issues.”

Graduate School Dean Jon Butler said his office will continue discussions about the upcoming strike with department chairs and directors of graduate studies to ensure that course instruction continues for undergraduates.