Section 6A. Any employee who is required as a condition of employment to be a member in good standing of a labor organization may file with the commission a charge alleging (1) that, although eligible to membership, he has been unfairly denied admission to, or unfairly suspended or expelled from membership in, such organization for reasons other than malfeasance in office or non-payment of regular initiation fees, dues, or assessments and (2) that such labor organization has requested, or is about to request, his employer to discharge or otherwise discriminate against him because of his failure to maintain membership in good standing in such organization; provided, that such charge shall be filed not more than fifteen days after notice of such request has been given the employee by the labor organization. Upon filing of such charge, the commission shall have power to issue and cause to be served upon the labor organization a complaint stating the charge in that respect and containing a notice of hearing. The notice shall be given and the subsequent proceedings shall be conducted in the manner provided in section six. If upon all the evidence the commission shall determine that the employee was unfairly denied admission to membership in such organization, or that such discipline—

(1) Was imposed by the labor organization in violation of its constitution and by-laws; or

(2) Was imposed without a fair trial, including an adequate hearing and opportunity to defend; or

(3) Was not warranted by the offense, if any, committed by the employee against the labor organization; or

(4) Is not consistent with the established public policy of the commonwealth;

then the commission shall state its determinations and shall issue and cause to be served on the labor organization an order requiring it, in its discretion, either to admit or restore the employee to membership in good standing together with full voting rights, or else to refrain from seeking to bring about any discrimination against him in his employment because he is not a member in good standing, and to return to him such union dues and assessments as may have been collected from him during the period of his suspension or expulsion from the union. If the commission shall not make such a determination after hearing, it shall enter an order dismissing the charge filed by the employee.

Nothing contained in this section or in section four shall be deemed to require a labor organization as a condition of making or enforcing a contract requiring membership therein as a condition of employment, to accord to non-participants in an insurance plan the right to vote on questions pertaining thereto or to grant local organizations voting rights in a convention proportionate to their membership.