Gary Smith, the union’s Scottish secretary, succeeds Tim Roache, who resigned last year after a series of allegations were made against him, which he has denied.
The Edinburgh-born former gas engineer, who now lives in Pasiley, beat the two other candidates, Rehana Azam and Giovanna Holt.
Smith took charge of the GMB's Scottish branch in 2015 and has been a persistent critic of the SNP Government's failure to secure more jobs from the offshore windfarm boom in recent years.
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