Metro's largest union has filed a federal lawsuit asking a court to enforce wage increases for bus and train operators.
The lawsuit filed Monday in Maryland comes after last week's announcement by Metro that it would ask for a review of an arbitration award that gave pay raises to about 7,700 workers. The award would give the employees 3 percent raises each year for the next three years.
Metro argues it cannot afford to pay approximately $100 million in pay raises.
The lawsuit by the Amalgamated Transit Union Local 689 asks the court to "confirm and enforce" the arbitrators' decision.