If you are called into a meeting with any management representative and have reason to believe that disciplinary action my result, read them your Weingarten rights...on could in any way lead to my being disciplined or terminated, or affect my personal working conditions, I respectfully request that my union representative or steward be present at this meeting. If this discussion could lead to my being disciplined and you deny my request for representation, I choose not to answer any questions."
In 1975 the U.S. Supreme Court ruled, in the Weingarten decision, that an employee is entitled to have a union representative present during any interview which my result in his or her discipline. It is up to you to insist on union representation. If you fail to do so, you may waive your rights.