The set of protections known as Weingarten Rights were created by a 1975 Supreme Court decision in the case of NLRB v. J. Weingarten, Inc. Weingarten rights protect union-represented workers during disciplinary interviews with management.
The Right to Union Representation
If you are called into an investigatory meeting and you have a reasonable belief that it may lead to discipline or discharge, you have the right to request union representation. Management has no obligation to inform you of this right. The burden is on you to make a clear request for union representation before or at any time during the interview. You cannot be punished for requesting a steward.
The Right to Decline to Answer Questions.
You have the right to decline to answer questions until your union representative arrives.
"I request to have my steward present at this meeting. Until my steward arrives, I choose not to participate in this meeting."
The Right to Know the Nature of the Complaint
You and your steward have the right to be informed of the subject matter of the investigation.