Union members have many rights, far too many to list here. You can review some of the broader rights on the NLRB website: http://www.nlrb.gov/. Others will be found in your union agreement. If you believe that your employer is violating your rights, speak with union management about the possibility of filing a grievance.
This answer is provided for guidance only. DO NOT rely on it as legal advice. We DO NOT have an attorney-client relationship. You should contact an attorney in your area for a one-on-one consultation before pursuing any action or making any decisions.
If you are a unionized employee, your relationship with your employer is governed by the Collective Bargaining Agreement ("CBA") between the union and your employer, and by the National Labor Relations Act ("NLRA"). I have provided a link to the Department of Labor's web page on the NLRA and employee rights.
If you want to understand your rights and your relationship with your employer, obtain a copy of the CBA and take a look at your rights under the NLRA.
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