Kelley slammed Musk and the Trump administration, saying the move showed "their utter disdain for federal employees and the critical services they provide to the American people."
"It is cruel and disrespectful to hundreds of thousands of veterans who are wearing their second uniform in the civil service to be forced to justify their job duties to this out-of-touch, privileged, unelected billionaire who has never performed one single hour of honest public service in his life," he said.
Several federal employees told AFP they were advised by their agencies not to respond to the email and wait for further instruction, a recommendation echoed by the National Treasury Employees Union.
"I have so much work to do, I am not going to neglect actual patient care for this drama," a physician at the Department of Veterans Affairs, who received the email, told AFP.