The Postal Service and the American Postal Workers Union say that they will continue negotiations to try and reach a contract agreement. The contract expired on Saturday. the APWU represents around 220,000 postal workers. Negotiations between the Postal Service and its other union, the National Rural Letter Carriers Association reached an impasse and will be decided by an arbitrator. If the Postal Service and the APWU also fail to reach an agreement, they will also go to arbitration. Postal workers cannot strike, and workers will continue under their old contracts until new ones are reached.
See "USPS continues talks with its largest union", Ed O'Keefe, The Washington Post, November 23, 2010