39 U.S. Code § 1208 - Suits
(a) The courts of the United States shall have jurisdiction with respect to actions brought by the National Labor Relations Board under this chapter to the same extent that they have jurisdiction with respect to actions under title 29.
(b) Suits for violation of contracts between the Postal Service and a labor organization representing Postal Service employees, or between any such labor organizations, may be brought in any district court of the United States having jurisdiction of the parties, without respect to the amount in controversy.
(c) A labor organization and the Postal Service shall be bound by the authorized acts of their agents. Any labor organization may sue or be sued as an entity and in behalf of the employees whom it represents in the courts of the United States. Any money judgment against a labor organization in a district court of the United States shall be enforcible only against the organization as an entity and against its assets, and shall not be enforcible against any individual member or his assets.
(d) For the purposes of actions and proceedings by or against labor organizations in the district courts of the United States, district courts shall be deemed to have jurisdiction of a labor organization
(2) in any district in which its duly authorized officers or agents are engaged in representing or acting for employee members.