In 1975 the United States Supreme Court in the case of NLRB v. J. Weingarten, Inc. 420 U.S. 251 (1975) upheld a National Labor Relations Board (NLRB) decision that employees have a right to union representation at investigatory interviews. These rights have become known as the Weingarten Rights.

During an investigatory interview, the Supreme Court ruled that the following rules apply:

Rule 1: The employee must make a clear request for union representation before or during the interview. The employee cannot be punished for making this request.

Rule 2: After the employee makes the request, the employer must choose from among three options:

• grant the request and delay questioning until the union representative arrives and (prior to the interview continuing) the representative has a chance to consult privately with the employee;
• deny the request and end the interview immediately; or
• give the employee a clear choice between having the interview without representation, or ending the interview.

Rule 3: If the employer denies the request for union representation, and continues to ask questions, it commits an unfair labor practice and the employee has a right to refuse to answer. The employer may not discipline the employee for such a refusal.