Members of UFCW Local 400 voted to authorize a strike, involving about 23,000 workers at Giant Food LLC and Safeway Inc. in the Baltimore and Washington metropolitan areas, if bargaining contracts cannot be reached by December 20. Union members at Giant and Safeway stores have not voted to strike since 1974. In the meantime, Giant and Safeway have begun to hire replacement or temporary workers at a starting salary of $12 an hour.

President Obama signed an executive order establishing a presidential emergency board in an effort to resolve a three-year impasse over contract negotiations between Long Island Rail Road Co. and seven unions. The three-member panel was appointed hours before the expiration of a mandatory 30-day cooling off period. The panel will investigate the dispute, hear evidence, and report to the President within 30 days. The unions and the railroad may either accept or reject the panel’s recommendations. Meanwhile, the parties are prohibited from making unilateral changes in existing working conditions for 120 days.

Nonunion drivers working for three trucking companies at the Port of Los Angeles engaged in work stoppages, alleging unfair labor practices and retaliation by their employers in response to the truckers’ efforts to form a union.