Voting will continue through Sept. 2 on all UC campuses and the results will be announced on Sept. 3.
Union leaders say the vote has been organized by a coalition of unions protesting Yudof's budgetary policies. They say they reject Yudof's contention that UC has a fiscal emergency.
Maricruz Manzanerez, a custodian at UC Berkeley and executive board member of the American Federation of State, County and Municipal Employees Local 3299 said in a statement, "While the state has reduced funding to UC, it represents less than 3 percent of UC's $20 billion annual budget."
Manzanerez said, "Rather than using the numerous reserves and resources of UC, Yudof proposes tuition hikes and devastating cuts to teaching, research, patient care and other vital services."
UC employees will be available at polling places at UC San Francisco at 513 Parnassus Ave. in San Francisco at noon Wednesday and at UC Berkeley at Telegraph and Bancroft avenues at noon Thursday.