officially Labor-Management Relations Act
(1947) U.S. legislation that restricted labour unions.
Sponsored by Sen. Robert A. Taft and Rep. Fred A. Hartley, Jr., the act amended much of the pro-union Wagner Act (1935) and was passed by a Republican-controlled Congress over the veto of Pres. Harry S. Truman . It allowed employees the right not to join unions (outlawing the closed shop ) and required advance notice of a labour strike, authorized an 80-day federal injunction when a strike threatened national health or safety, narrowed the definition of unfair labour practices, specified unfair union practices, restricted union political contributions, and required union officials to take an oath pledging they were not communists. See also Landrum-Griffin Act .