Microsoft workers are calling on their employer to cancel a $480m contract to provide the US army with augmented reality (AR) headsets, saying they “do not want to become war profiteers”.

“We did not sign up to develop weapons, and we demand a say in how our work is used,” reads a petition being circulated inside the company, a copy of which was published on Twitter on Friday afternoon. More than 50 employees had signed the letter as of Friday afternoon, according to an employee.

The employee protest is the latest manifestation of a growing labor movement in the US technology industry. Employees at companies including Microsoft, Google, Amazon and Salesforce are increasingly speaking out both about their own working conditions and about the uses to which their employees put their work product.

Microsoft’s HoloLens, a $3,000 AR headset that is somewhere in between the ill-fated Google Glass and the fully immersive Oculus, was developed out of a technology called Kinect that was part of the company’s Xbox video gaming system.

Many of the engineers who worked on building the technology believed “it would be used to help architects and engineers build buildings and cars, to help teach people how to perform surgery or play the piano, to push the boundaries of gaming, and to connect with the Mars Rover (RIP)”, the letter states.

Under the terms of the army contract, however, the devices will be used to “increase lethality by enhancing the ability to detect, decide and engage before the enemy”, according to Bloomberg.

“While [Microsoft] has previously licensed tech to the US Military, it has never crossed the line into weapons development,” the letter states. “With this contract, it does. The application of HoloLens within the IVAS system is designed to help people kill. It will be deployed on the battlefield, and works by turning warfare into a simulated ‘video game’, further distancing soldiers from the grim stakes of war and the reality of bloodshed.”

Microsoft’s HoloLens, a wireless helmet that creates holographic images in front of the wearer. Photograph: Microsoft/REX/Microsoft/Rex

In addition to canceling the HoloLens contracts, the letter calls on Microsoft to cease working on “any and all weapons technologies”, to create a public “acceptable use policy” codifying such a commitment, and to create an “independent, external ethics review board” to enforce compliance with such a policy.

In June 2018, more than 100 Microsoft employees signed a petition protesting against their employer’s contract with Immigration and Customs Enforcement. And in October, anonymous employees published an open letter on Medium calling on the company not to bid on a contract to build cloud services for the defense department.

At the time, the Microsoft president, Brad Smith, defended the company’s decision to support the US military, writing in a blogpost: “We want the people of this country and especially the people who serve this country to know that we at Microsoft have their backs.” He also said that Microsoft would advocate for policies and laws to ensure that technology was used “responsibly and ethically” and that the company would “support talent mobility” for employees who did not want to work on certain projects “for whatever reason”.

“We always appreciate feedback from employees and have many avenues for employee voices to be heard,” a Microsoft spokesperson said in response to the petition.