May another employer's employees picket a neutral employer?
Author: Irene Stavrellis Englert, Englert Legal Consulting, LLC
No. Commonly known as secondary picketing or secondary boycott, the picketing of a neutral employer is unlawful under the National Labor Relations Act. Unions primarily engage in secondary boycotts in an attempt to bring pressure on neutral third parties in hopes that they will, in turn, put pressure on the employer with whom they have a dispute to give in to the union's demands.
However, the distinction between the primary employer and supposed neutral employer may not always be clear. For example, under the ally doctrine, if the primary employer was unable to supply its customers due to a strike and sent work to another employer, the union could picket that employer as well as the primary employer.