A bill to amend the National Labor Relations Act and the Railway Labor Act to prevent discrimination based on participation in labor disputes.

Amends the National Labor Relations Act to make it an unfair labor practice for an employer to promise, threaten, or take other action to hire a permanent replacement for an employee who: (1) at the beginning of a labor dispute was in a bargaining unit in which a labor organization either was the certified or recognized exclusive representative or was seeking to be so certified or recognized, on the basis of written authorizations by a majority of unit employees; and (2) in connection with that dispute has engaged in concerted activities for collective bargaining or other mutual aid and protection through that labor organization.

Makes it also an unfair labor practice for an employer to withhold or deny any other employment right or privilege to such an employee who is working for or has unconditionally offered to return to work for the employer, out of preference for any other individual based on that individual's performing, having performed, or having indicated a willingness to perform bargaining unit work for the employer during the dispute.

Allows employers to hire permanent replacements for such employees in gradually increasing proportions after specified durations, beginning with ten percent after 60 days of the dispute and ending with 100 percent after 360 days of the dispute.

Amends the Railway Labor Act to prohibit any carrier or its officer or agent from discriminating against an employee in a craft or class in any of the above ways prohibited to employers under the National Labor Relations Act. Allows hiring of permanent replacements in similar proportions after similar durations of the dispute.