Unions representing Carpenters and Teamsters at the Pennsylvania Convention Center filed unfair labor practice charges with the National Labor Relations Board in Philadelphia late Monday afternoon.
The Convention Center's management has "engaged in bad faith bargaining," according to paperwork filed by the Metropolitan Regional Council of Carpenters Local 8.
A similar charge was filed by the International Brotherhood of Teamsters Local 107, its leader, William Hamilton said.
The documents seek injunctive relief and are filed against the Pennsylvania Convention Center Authority as well as its management company, SMG, and its labor broker, Elliott-Lewis Corp.
The NLRB filing repeats the Carpenters' argument that they believed they had a contract extension until May 10, and that the customer satisfaction agreement was included in that.
Convention Center spokesman Pete Peterson said management was not aware of the filing.