United Steelworkers (USW) members at Tesoro's Mandan, North Dakota, refinery voted overwhelmingly Thursday to give their negotiating committee the authority to call a strike. At this time a strike has not been called.

"Given Tesoro's refusal to put forward fair proposals at the bargaining table, our members thought it was important to take this step in authorizing the committee to call a strike if needed," said USW Local 10 President Javier Montoya. "If the company continues to refuse to put forward an offer that our membership can find acceptable, we will have to consider using our authority to call a strike."

The Mandan workers join other USW members at Tesoro refineries in Anacortes, Wash., and Martinez, Calif., in giving strike authorization to their bargaining committees. Currently, workers at refineries accounting for 61% of the company's refining capacity have authorized strike action. On May 1 when the contract covering workers at the company's Los Angeles refinery expires, workers at refineries accounting for 78% of the company's capacity will be in a position to strike if needed.

During negotiations Tesoro has been attempting to get the local unions to agree to waive their legal right to bargain over benefit changes during the term of the agreement. Six months after members lost seven co-workers due to the April 2, 2010 Good Friday explosion and fire at the Anacortes refinery, the company announced it was cutting or eliminating benefits.

Despite the locals' demands to bargain, Tesoro unilaterally implemented a series of benefit reductions on Jan. 1, 2011. The USW filed unfair labor practice charges. At Mandan, a National Labor Relations Board (NLRB) administrative law judge ruled Feb. 7, 2012 that the company should have bargained with the union and unlawfully implemented the benefit cuts. The judge ordered Tesoro to bargain with the union over the changes, restore the original benefits and reimburse workers for any increased costs resulting from the benefit cuts. Tesoro has appealed the decision.

Other contract issues include calculation of vacation time, pension security and restoration of retirement benefits.