Tesla’s big promises and Wall Street valuation have come with added pressure from its employees and the labor community.

Nearly 60 local organizations sent a letter to CEO Elon Musk this week criticizing the tech company’s confidentiality policy and safety protocol at its Fremont factory. Tesla also operates a design center in Hawthorne, where Musk’s SpaceX rocket manufacturing company also is located.

Workers and advocates say the pressure to increase production has led to an unsafe and difficult factory environment. The letter, part of an effort to unionize the plant, also calls for the automaker to loosen its confidentiality policy and allow workers to more freely discuss issues at the plant.

“The workers feel they do not have a mechanism to discuss problems,” said Derecka Mehrens, co-founder of Silicon Valley Rising, a worker advocacy group. “A union, fundamentally, provides workers a voice.”

The company did not immediately respond to a request for comment. Musk has said Tesla’s priority is to create a safe and fair workplace, and that factory worker wages are competitive when benefits and a stock purchasing program are factored in. The campaign comes as investors have pushed Tesla’s market value over established automakers Ford and GM.

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The company answered similar criticisms from California lawmakers in January, saying its confidentiality statement did not curb legal communications between workers and outside agencies.

But the labor organizations expressed concern that the electric vehicle maker fails to place enough emphasis on safety and worker protections. The concerns could only grow as Tesla seeks to speed up production from 84,000 to 500,000 vehicles by next year. Tesla workers have reached out to the United Automobile Workers for help in organizing.

The groups took aim at Tesla’s confidentiality agreement, saying it chills discussions about work conditions. The letter said the company can protect both trade secrets and worker rights.

“While we respect the need for Tesla to protect critical information about its products and technology, this agreement fails to acknowledge the protected rights of workers to communicate to each other and to the public about their working conditions, wages, or other critical worker justice issues,” the groups said.

The groups include the labor councils of the South Bay AFL-CIO, San Francisco and Alameda, local chapters of the UAW, and several other environmental and worker advocacy organizations.

Michael Catura, a Tesla production worker, said he believes in the company’s clean energy mission but worries that the workers do not have enough say on the factory floor. Safety measures — including precautions against repetitive stress injuries — are not standardized across the production line, he said.

Catura, 32, expects the pressure to ratchet up in the coming months for the production of the company’s new sedan, the Model 3.

“I don’t know how much faster and harder they want us to work,” he said.