The labor union of Hyundai Motor [part of Hyundai Kia Motor] has threatened to suspend all engine output in the company's biggest production base…saying an employee set himself on fire to protest the company's alleged "suppression" of unionized workers…The worker and union member with the surname Shin was found in flames at a Hyundai engine plant in the southeastern city of Ulsan…and is currently in critical condition at a hospital…The union said…that a factory manager had tried to "unfairly control" Shin after he reported problems with engine quality to management…A company spokesman denied any improper conduct in the treatment of unionized workers…"The police are investigating (Shin's) case and we are keeping an eye on the probe," the spokesman said.