Criminal Law Questions? Ask a Criminal Lawyer.
Because you are a union member, you have all the rights under the collective bargaining agreement to "just cause" in your employment - this means a fair and accurate investigation and procedure - along with a right to be heard. Also, you need to file a grievance against the company for your termination - you have the absolute right to do that. Likewise, if the grievance is rejected, you can request your union file arbitration for you.
If the union ultimately fails to do these things for you - there are two courses of action you can take -1) is to file an unfair labor practice against the union for failure to represent you. These are free of charge and you can follow the process at this link http://www.nlrb.gov/what-we-do/investigate-charges 2) is to file a Section 301 Labor Management Relations Act (LMRA) claim against both the employer and union in federal court. With the Section 301 claim you would indeed have to hire your own attorney. In the 301 claim you are essentially suing the employer (because it violated the collective bargaining agreement) and the Union (because it did not properly represent you).
I believe this answers your question. However, if you need clarification or have follow-up questions regarding this matter, I will be happy to continue our conversation – simply reply to this answer. If you are otherwise satisfied with my response, please leave a positive rating as itis the only way I am able to get credit for my answers. Thank you, ***** ***** wish you all the best with this matter.