Billionaire Trump adviser Elon Musk violated the law with his weekend demand that federal employees explain their accomplishments or risk being fired, attorneys for the workers said Monday in a lawsuit.

The updated lawsuit, which was filed in federal court in California and was provided to The Associated Press, is trying to block mass layoffs pursued by Musk and President Donald Trump, including any connected to the email distributed by the Office of Personnel Management on Saturday. The office, which functions as a human resources agency for the federal government, said employees needed to detail five things they did last week by end of day on Monday.

“No OPM rule, regulation, policy, or program has ever, in United States history, purported to require all federal workers to submit reports to OPM,” said the amended complaint, which was filed on behalf of unions, businesses veterans, and conservation organizations represented by the group State Democracy Defenders Fund. It called the threat of mass firings “one of the most massive employment frauds in the history of this country.”

Musk, who’s leading the Republican president’s efforts to overhaul and downsize the federal government, continued to threaten federal workers Monday even as confusion spread through the administration and some top officials told employees not to comply.

“Those who do not take this email seriously will soon be furthering their career elsewhere,” Musk posted on X, his social media platform.

He also escalated Trump’s demand for employees to stop working remotely, saying those who fail to return to the office will be placed on administrative leave.

The latest round of turmoil began over the weekend, when Trump posted on his social media website: “ELON IS DOING A GREAT JOB, BUT I WOULD LIKE TO SEE HIM GET MORE AGGRESSIVE.”

Musk followed by saying “all federal employees will shortly receive an email requesting to understand what they got done last week.” He claimed “failure to respond will be taken as a resignation.” The directive echoed how the entrepreneur has managed his own companies.

The Office of Personnel Management sent out its own request afterward.

“Please reply to this email with approx. 5 bullets of what you accomplished last week and cc your manager,” the message said. However, it said nothing about the potential for employees being fired for noncompliance. The deadline was listed as 11:59 p.m. EST Monday.

There was swift resistance from several key U.S. agencies led by the president’s loyalists — including the FBI, the State Department, Homeland Security and the Pentagon — which instructed their employees over the weekend not to respond. Lawmakers in both major political parties said Musk’s mandate may be illegal, while unions threatened to sue.

One message Sunday morning from the Department of Health and Human Services, led by Robert F. Kennedy Jr., instructed its 80,000 employees to comply. That was shortly after the acting general counsel, Sean Keveney, had instructed some not to. And by Sunday evening, agency leadership issued new instructions that employees should “pause activities” related to the request until noon Monday.