Sheet Metal Workers' International Ass'n, Local 15 v. National Labor Relations Board

Opinion for the Court filed by Chief Judge GINSBURG.

GINSBURG, Chief Judge.

In the course of a labor dispute with Energy Air, a heating, ventilation, and air conditioning contractor, Sheet Metal Workers’ Local 15, AFL-CIO notified Beall’s, Inc. — a department store for which Energy Air was performing mechanical work — that the Union “will be compelled” to publicize its dispute with Energy Air at two of Beall’s department store construction sites. The Union’s letter to Beall’s did not contain the assurance required by the National Labor Relations Board that the Union’s picketing would conform to…