OAKLAND — An overwhelming number of voting teachers authorized the Oakland teachers union to call a strike if salary negotiations break down with the school district, which already is facing another major disruption in the form of a $30 million budget deficit.

The 3,000 members of the Oakland Education Association voted from Jan. 29 through Feb. 1. Of the 84 percent of union members voting, 95 percent approved authorizing union leaders to call a strike if necessary, union president Keith Brown announced Monday.

“This is a clear message that our members are ready to fight for the schools our students deserve,” Brown said. No date was set, but the union expects if a strike were to occur it would happen by the end of the month.

Oakland Unified spokesman John Sasaki said Monday the district hopes that it doesn’t come to that. Though substitutes would be brought in to cover for striking teachers, a strike could be very disruptive to students, especially those preparing for end-of-the-year exams.

The union has been without a contract since July 2017, and has been pushing for a 12 percent raise over three years, smaller class sizes and the hiring of additional counselors and nurses. The district has offered a 5 percent raise over three years.

The strike vote followed two non-union-sanctioned “sick-outs” by Oakland teachers in December and January. Both times, teachers called in sick and instead rallied in support of a strike.

The average Oakland teacher’s yearly salary was $63,149 during the 2017-18 school year, according to a report from the state’s Department of Education. Starting salary was $46,570, with highest paid teachers at $83,724.

Oakland’s last sanctioned teacher strike was in 2010, and lasted one day. A 26-day teacher strike occurred in 1996.

District officials in the past have said they would like to offer teachers more pay, but their hands are tied as they deal with a budget deficit expected to reach $56 million by the 2020-21 school year. The school board is looking to cut as much as $30 million from next year’s budget and close as many as 24 schools over the next five years.

The district estimates it will cost about $3.5 million a year for each 1 percent raise, superintendent Kyla Johnson-Trammell said in an email to parents, students and faculty last week.

District officials have been campaigning at the state level for more money to go to schools, she said.

This story is developing, check back for more information.