Tech giant Google recently told its employees they will lose pay, and ultimately their jobs, if they don’t abide by the company’s vaccination policy, CNBC reports.

CNBC viewed the memo circulated by leadership, which said that employees had until Dec. 3 to inform the company of their vaccination status and upload documentation showing proof, or to request a medical or religious exemption. After the Dec. 3 deadline, Google said it would start getting in touch with employees who hadn’t uploaded their status or were unvaccinated. The company would also contact those whose exemption applications weren’t approved.

According to the document, employees who haven’t adhered to the vaccination requirements by the Jan. 18 deadline will be put on “paid administrative leave” for 30 days. If employees remain in conflict with the company’s rules, they will be placed on “unpaid personal leave” for up to six months, after which they’ll be fired.

Over the course of the Covid-19 pandemic, companies of all sizes across all sectors have been forced to reevaluate their workforce models, with many settling on a hybrid future that still allows for some flexibility. Google will require its employees to come into the office three days a week at some point in 2022.

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In early November, the Biden administration ordered U.S. companies with 100 or more workers to fully vaccinate their employees or subject them to regular testing by Jan. 18. A federal court blocked the mandate, but Google has moved forward with its vaccination plans, requesting that its more than 150,000 employees upload their proof of vaccination, regardless of whether they intend to return to the office or not. Google’s requirements would even apply to employees working from home who interact directly or indirectly with federal government contracts.

“We expect that almost all roles at Google in the United States will fall within the scope of the executive order,” Google’s internal documents read. “Anyone entering a Google building must be fully vaccinated or have an approved accommodation that allows them to work or come onsite,” the company said, making it clear that “frequent testing is not a valid alternative to vaccination.”

Hundreds of Google employees have signed and circulated a manifesto opposing the company’s requirements. The company has suggested those employees who prefer not to be vaccinated and aren’t approved for an exemption “explore” other roles at the company that don’t conflict with the Biden administration’s mandate. Employees whose roles aren’t included in the executive order will be able to “permanently work remotely going forward,” the company said, if their duties don’t require visits to the office.