An employer's discharge of an employee because of his union activities or sympathies violates section 8(a)(3) of the Act, 29 U.S.C. § 158(a)(3). The existence of a justifiable ground for discharge will not prevent such discharge from being an unfair labor practice if partially motivated by the employee's protected activity; a business reason cannot be used as a pretext for a discriminatory firing. Martinez and Rios were employed by P. Zamora, their supervisor, fired both men for failing to complete work in a timely manner. Zamora testified that he observed Rios and Martinez working slowly and watching several women sunbathe in bikinis some distance from the employees' worksite. Upset with their performance, Zamora approached Rios and Martinez and stated that 'if you want to see girls wearing bikinis there were some better ones at the beach.' Zamora then left, verified with his superior that he had the authority to fire, returned, and discharged the two men. Martinez and Rios filed a complaint with D claiming they were wrongfully discharged because they were engaged in union organizing activity on three separate incidents occurring over a six-month period coinciding with union efforts to organize some of P’s employees. During the trial, the administrative law judge discredited much of Rios’ testimony in the strongest terms. He noted that 'Rios 'fabricated facts in an effort to make Zamora appear as a scoundrel.' In light of this conflicting testimony, the ALJ believed Zamora, whom he characterized 'as an honest and forthright witness,' and disbelieved Employee Ruiz, whose testimony he characterized as 'equivocal.' Martinez admitted that he was working at a slow pace on the day he was fired. Other evidence showed that several months prior to the discharge, Zamora and another supervisor watched for 5 or 10 minutes while Rios and two other employees stood under a tree, doing no work. When Zamora approached and demanded an explanation, the employees stated that they had no work to do and were waiting for quitting time. Zamora then suspended them The ALJ found from most of the evidence that the Union was the topic of discussion but no coercion occurred. The judge held for P and Martinez and Rios appealed. The keystone of the administrative law judge's finding of proper motive was his conviction that Zamora told the truth. D reversed the decision and held that P had engaged in coercive interrogation of employees in violation of section 8(a)(1). P appealed.