You have the right to a union steward in any meeting with management that could potentially result in discipline. This is called your Weingarten Rights, named after a supreme court decision.

If you’re called into a meeting with management, you should say something like: “If this discussion could in any way lead to my being disciplined or terminated, or affect my personal working conditions, I request that my steward (or a union officer) be present. Without representation, I choose not to answer any questions. This is my legal right.”