It is an unfair labor practice for an employer, by discrimination in regard to hire or tenure of employment or any term or condition of employment, to encourage or discourage membership in a labor organization. However:

1. (1) Nothing in this chapter or in any other statute of this state precludes an employer from making an agreement with a labor organization (not established, maintained or assisted by any action defined in this section or in ORS 663.120 as an unfair labor practice) to require as a condition of employment membership therein on or after the 30th day following the beginning of such employment or the effective date of such agreement, whichever is the later:

   1. (a) If the labor organization is the representative of the majority of the employees in the appropriate collective-bargaining unit covered by the agreement when made; and
   2. (b) Unless following an election held within one year preceding the effective date of the agreement, at least a majority of the employees eligible to vote in the election have voted to rescind the authority of the labor organization to make such an agreement.

2. (2) No employer shall justify any discrimination against an employee for nonmembership in a labor organization if the employer has reasonable grounds for believing that membership was:

   1. (a) Not available to the employee on the same terms and conditions generally applicable to other members; or
   2. (b) Denied or terminated for reasons other than the failure of the employee to tender the periodic dues and the initiation fees uniformly required as a condition of acquiring or retaining membership.

[1971 c.729 §8]