GM labor dispute in Mexico a concern

US lawmakers joined global labor advocacy groups last week in putting pressure on General Motors to ensure worker rights at its Silao plant in Mexico. The automaker’s union there has been accused of tampering with a worker vote. Mexico’s labor ministry said that some ballots were destroyed during a unionled vote in April for workers to ratify their collective contract. The vote is required under a Mexican labor reform to ensure workers are not bound to so-called protection contracts, which are signed between behind workers’ backs and prioritize company interests.