More than 500 workers at a Chevron Corp. refinery in the San Francisco Bay area have told the company they will go on strike at 12:01 a.m. Monday.
Members of United Steelworkers Local 5 voted down the company's most recent contract offer and gave notice of intent to go on strike, the union said in a statement Sunday.
The statement says Chevron refused to return to the bargaining table.
Messages were left Sunday seeking comment from Chevron.
If the strike shuts down the Richmond, California, refinery, it could crimp gasoline supplies in the state, which has the highest regular gas price in the nation at $5.847 per gallon, according to AAA.
The union said in its statement that it reached a pattern agreement with the oil industry Feb. 25 on wages and working conditions. But about 200 bargaining units also have to agree on local issues before contracts can be approved.
The old contract with Chevron in Richmond expired Feb. 1, and workers have been reporting to their jobs on a rolling 24-hour extension, the union said.
The San Ramon, California-based Chevron says on its website that the refinery produces gasoline, diesel and jet fuel, as well as lubricating oils.