Weingarten Rights

Union members have the right to representation by a union steward or union representative during any conversations with management or security that may lead to discipline. These discussions include if a union member is asked to defend his/her conduct, and includes discussions that may affect the member's working conditions or in disciplinary actions.

Management is not obligated to provide you with union representation, or even inform you of this right. You must ask for representation. However, once you request union representation, the law requires the company to provide you with representation, or they must end the interview.