No court of the United States, as defined in this chapter, shall have jurisdiction to issue any restraining order or temporary or permanent injunction in a case involving or growing out of a labor dispute, except in a strict conformity with the provisions of this chapter; nor shall any such restraining order or temporary or permanent injunction be issued contrary to the public policy declared in this chapter.
(Mar. 23, 1932, ch. 90, § 1, 47 Stat. 70.)