Construction workers who helped build Tesla's massive factory in Austin, Texas alleged they were short-changed their pay and faced exploitative conditions and have filed complaints with the U.S. Labor Department.

The Workers Defense Project filed two labor standards violation referrals on Tuesday alleging improper overtime pay and false labor certificates.

Gigafactory Austin
Gigafactory In Austin, Texas Tesla

The complaint alleges workers were short-changed their pay on numerous occasions.

The WDP tweeted Elon Musk, and Tesla accounts directly, ahead of filing the complaint.

The WDP also filed a second complaint alleging that an undisclosed Tesla subcontractor fabricated a workplace safety training certificate for a worker.

The Department of Labor requires construction industry employers to comply with federal safety training standards to prevent their employees from potential injury.

WDP also asked Travis County commissioners to adopt Better Builder Standards in all new construction projects. These standards created by the WDP include "a living wage, OSHA-certified safety training, goals to hire from apprenticeship programs, workers' compensation, and independent Better Builder certified on-site monitoring," according to a press release.

The federal complaint comes as Elon Musk recently asked employees at this other company, Twitter, to work long hours or risk losing their jobs. Musk has also fired 3,700 full-time employees and several contractors without notice while initiating "Twitter 2.0."

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