(Reuters) -More than 500 Amazon.com ( AMZN ) employees sent a letter on Wednesday to the CEO of its AWS unit urging reversal of a full return-to-office policy and rejecting his assertion that the rule had broad support and opponents should leave Amazon Web Services.

"We were appalled to hear the non-data-driven explanation you gave for Amazon ( AMZN ) imposing a five-day in-office mandate," the letter begins.

AWS CEO Matt Garman, at an Oct. 17 all-hands meeting of the cloud computing unit, said nine out of 10 workers he had spoken with supported the return-to-office policy, set to take effect early next year.

Those comments are "inconsistent with the experiences of many employees" and are "misrepresenting the realities of working at Amazon ( AMZN )," according to the letter, which Reuters reviewed after it was sent to Garman.

Amazon ( AMZN ) had no immediate comment, said a spokesperson.

Garman had said he was "quite excited about this change" and that, under the current three-day-per-week policy, collaboration was too difficult because people may be in offices on different days.

The company-wide policy, announced in September by Amazon ( AMZN ) CEO Andy Jassy, has been controversial inside Amazon ( AMZN ), with many calling it wasteful because it adds commuting time and expense when remote work has been effective. Some say they plan to leave the company. Amazon ( AMZN ) has enforced the policy by asking many workers to go to regional offices, move to Seattle or "voluntarily resign."

Garman's comments do not reflect any independent data, the letter says, and "break the trust of your employees who have not only personal experience that shows the benefits of remote work, but have seen the extensive data which supports that experience."

Requiring five days in the office every week also particularly impacts protected classes of workers such as those with neurodiversity or childcare responsibilities and "does not uphold Amazon's ( AMZN ) espoused "Strive to be Earth's Best Employer" leadership principle," according to the letter.

Attached to the letter were anonymous stories from a dozen Amazon ( AMZN ) workers who said complying with a five-day in-office policy would be difficult or impossible, due to, among others, family obligations, commuting times or medical necessities.

One said the closest office is four hours away; another said their spouse would be forced to quit her job to accommodate a move across the country; and another said they are more efficient working from home.

"I used to be proud of my work and excited about my future here," said one. "I don't feel that anymore."

The letter linked to a 2020 blog post in which Garman wrote AWS had been running effectively at the outset of the pandemic when most workers were remote.

Amazon ( AMZN ) has taken a stricter approach to return-to-office mandates than many of its tech peers who are enforcing two- and three-day policies. The company has said the policy helps workers "invent, collaborate and be connected" and Garman suggested "we didn't really accomplish anything" under the three-day policy.