Several hundred Google employees have signed and circulated a manifesto opposing the company’s vaccine mandate, posing the latest challenge for leadership as it approaches key deadlines for returning workers to offices in person.

The Biden administration has ordered U.S. companies with 100 or more workers to ensure their employees are fully vaccinated or regularly tested for Covid-19 by Jan. 4. In response, Google has asked its more than 150,000 employees to upload their vaccination status to its internal systems by Dec. 3, whether they plan on coming into the office or not, according to internal documents viewed by CNBC. The company has also said that all employees who work directly or indirectly with government contracts must be vaccinated — even if they are working from home.

“Vaccines are key to our ability to enable a safe return to office for everyone and minimize the spread of Covid-19 in our communities, wrote Chris Rackow, Google VP of security, in an email sent near the end of October.

Rackow stated the company was already implementing requirements, so the changes from Biden’s executive order were “minimal.” His email gave a deadline of Nov. 12 for employees to request exemptions for reasons such as religious beliefs or medical conditions, and said that cases would be decided on a case-by-case basis.

The manifesto within Google, which has been signed by at least 600 Google employees, asks company leaders to retract the vaccine mandate and create a new one that is “inclusive of all Googlers,” arguing leadership’s decision will have outsized influence in corporate America. It also calls on employees to “oppose the mandate as a matter of principle” and tells employees to not let the policy alter their decision if they’ve already chosen not to receive the Covid-19 shot.

The manifesto comes as most of the Google workforce approaches a deadline to return to physical offices three days a week starting Jan. 10. The company’s notably outspoken employees have previously debated everything from government contracts to cafeteria food changes. 

A spokesperson for Google said the company stands behind its policy. “As we’ve stated to all our employees and the author of this document, our vaccination requirements are one of the most important ways we can keep our workforce safe and keep our services running. We firmly stand behind our vaccination policy.”

Vaccination is a dilemma not only for Google, but for corporate America in general. The Covid-19 virus has contributed to 772,570 deaths in the U.S., according to Johns Hopkins data. Despite proven effectiveness in providing a high level of protection against hospitalization and death, the country is struggling to persuade millions of people to get their first dose, as more than 60 million Americans remain unvaccinated.

In July, CEO Sundar Pichai announced the company would require vaccinations for those returning to offices. In October, Pichai said that the San Francisco Bay Area offices, near its headquarters, are up to 30% filled while New York is seeing nearly half of its employees back. He added at that time that employees who don’t want to get vaccinated would be able to continue working remotely. 

The company has taken other steps to convince employees to get vaccinated as well. For instance, Joe Kava, vice president of data centers at Google, announced a $5,000 vaccination incentive spot bonus for U.S. data center employees, according to the manifesto.

In an email cited in the manifesto and viewed by CNBC, Google VP of global security Chris Rackow said that because of the company’s work with the federal government, which “today encompasses products and services spanning Ads, Cloud Maps, Workspace and more,” all employees working directly or indirectly with government contracts will require vaccinations — even if they are working from home. Frequent testing is “not a valid alternative,” he added.

The authors of the manifesto strongly disagree.

“I believe that Sundar’s Vaccine Mandate is deeply flawed,” the manifesto states, calling company leadership “coercive,” and “the antithesis of inclusion.” 

In a subhead titled “Respect the User,” the authors write that the mandate of “barring unvaccinated Googlers from the office publicly and possibly embarrassingly exposes a private choice as it would be difficult for the Googler not to reveal why they cannot return.”

The author also argues the mandate violates the company’s principles of inclusiveness.

“Such Googlers may never feel comfortable expressing their true sentiments about a company health policy and other, unrelated sensitive topics. This results in silenced perspective and exacerbates the internal ideological ‘echo chamber’ which folks both inside and outside of Google have observed for years.”

The manifesto also opposes Google having a record of employees’ vaccination status.

“I do not believe Google should be privy to the health and medical history of Googlers and the vaccination status is no exception.” Google has asked employees to upload their vaccination proof to Google’s “environmental health and safety” team even if they already uploaded it to One Medical, one of Google’s benefits providers, according to internal documentation.

The author then tries to argue the vaccine mandate may be the start of a slippery slope, paving the way for other intrusive measures — a common line of argument among people opposed to the mandates.

“It normalizes medical intervention compulsion not only for Covid-19 vaccination but for future vaccines and possibly even non-vaccine interventions by extension. It justifies the principle of division and unequal treatment of Googlers based on their personal beliefs and decisions. The implications are chilling. Due to its presence as an industry leader, Google’s mandate will influence companies around the world to consider these as acceptable tradeoffs.”

The group has sent these concerns in an open letter to Google’s chief health officer Karen DeSalvo, the document states.

In Google’s most recent all-hands meeting, called TGIF, some employees attempted to bring more attention to the vaccine question by getting fellow employees “downvote” other questions in an internal system called Dory, according to an internal email chain viewed by CNBC. The goal was to ensure their questions would gain enough votes to qualify for executives to address them.

The pushback against vaccine mandates poses a new challenge for Google’s leadership at a time when it is trying to target the healthcare industry among its growing business ambitions — particularly for its cloud unit. 

In August, Google disbanded its health unit as a formalized business unit for the health-care sector and Dr. David Feinberg, who spent the past two years leading the search giant’s health care unit, left the company. Nonetheless, Google Cloud CEO Thomas Kurian has routinely mentioned healthcare sector as a key focus area and DeSalvo, an ex-Obama administrator whom Google hired as its first health chief in 2019, told CNBC’s “Squawk Box” last month the tech giant is “still all in on health.”

The company has tried to capitalize on the broader fight against Covid in several ways. In the first half of 2021, the company spent nearly $30 million on at-home Covid tests for employees from Cue Health, which went public in September at a $3 billion valuation. Shortly after, the company announced a separate partnership with Google’s cloud unit to collect and analyze Covid-19 data with hopes of predicting future variants. Google also teamed up with Apple for an opt-in contract tracing software in hopes of tracking Covid-19.