Six U.S. senators representing West Coast states today urged the International Longshore and Warehouse Union (ILWU), which represents 13,600 workers at 29 West Coast ports, and the Pacific Maritime Association (PMA), which represents ship lines and terminal operators, to quickly come to terms on a new collective bargaining agreement and end the six month stalemate that now threatens to paralyze maritime traffic from Seattle to San Diego.

In a letter to the heads of PMA and ILWU, the senators called on both sides to "continue negotiating in good faith to resolve the remaining issues and to swiftly move toward a final contract agreeable to both parties." The letter was signed by Sens. Patty Murray, D-Wash.; Maria Cantwell, D-Wash.; Barbara Boxer, D-Calif.; Dianne Feinstein, D-Calif.; Ron Wyden, D-Ore.; and Jeff Merkley, D-Ore.

Last week, a coalition of 100 business groups called on President Obama to encourage both parties to work with a federal mediator in an effort to reach an accord and to exercise his authority to intervene under the Taft-Hartley Act should there be a strike or lockout. The last time the White House intervened in a port dispute was in October 2002, when President Bush invoked language in Taft-Hartley to end a 10-day lockout of labor on the West Coast.

The PMA had charged ILWU with orchestrating a work slowdown at the twin ports of Seattle and Tacoma, Wash., and with failing to fill key worker positions at the ports of Los Angeles and Long Beach, the country's busiest seaports. The union declined to comment on the allegations. There were also reports of job actions at the Port of Oakland, though port officials there could not confirm the reports.

The six-year contract signed in 2008 expired on July 1. Since then, the parties have continued bargaining, and the 29 ports have operated as normal. Both sides announced in August that they had reached a tentative agreement on health benefits. Otherwise, however, talks have made scant progress.