The one-day strike is about workers being asked to take another 10 percent pay cut.
Union workers plan to start picketing in front of Oakland City Hall at Frank Ogawa Plaza at 6 a.m., barring a last-minute agreement.
Union leaders have filed four unfair labor practice charges claiming the city is not bargaining in good faith.
Mayor Jean Quan has said the city is doing everything it can to avert a strike.
