FBI Director Kash Patel directed bureau staff Saturday to not respond to an email sent from the Office of Personnel Management — and supported by Elon Musk — demanding that federal workers justify their jobs or resign, as news broke that he would be tapped to be the acting head of a second federal law enforcement agency. 

The email to federal workers demanding that they detail what they did in the past week was sent out Saturday from the Office of Personnel Management, shortly after Musk posted on X that such a demand was forthcoming, according to multiple sources, ABC News reported.

Patel, who was sworn in to his 10-year term on Friday, responded by instructing his workers they they should not answer the demand letter.

“FBI personnel may have received an email from OPM requesting information,” Patel said in his message, the outlet reported.

“The FBI, through the Office of the Director, is in charge of all of our review processes, and will conduct reviews in accordance with FBI procedures. When and if further information is required, we will coordinate the responses. For now, please pause any response.”

The threatening emails were sent after Musk, the Department of Government Efficiency honcho, posted on X that “all federal employees will shortly receive an email requesting to understand what they got done last week.”

The SpaceX founder said failure to respond to his demands would be treated as a resignation. 

The OPM email laid out a Monday deadline to respond but failed to include any mention that a non-answer would be considered a resignation, CNN reported.

The tech billionaire, who is an unpaid “special government employee,” has already fired thousands of government workers and shut down entire agencies without congressional approval. 

The richest man alive is aiming to slash $1 trillion from the federal deficit, along with his team of 100 cost-cutters. 

The latest federal shake-up comes as President Trump is expected to appoint Patel, 44, to head up the Bureau of Alcohol, Tobacco, Firearms and Explosives, a Justice Department official told ABC News. 

He is set to be sworn in as the law enforcement agency’s acting director next week. 

The White House did not immediately respond to The Post’s request for comment.

The move to have Patel serve double-duty comes after Attorney General Pam Bondi fired the ATF’s general counsel, Pamela Hicks, on Thursday. 

Bondi told Fox News the termination stemmed from the agency’s top lawyer “targeting gun owners.”

Hicks, who served as deputy chief counsel for ATF during Trump’s first stint as president, was the agency’s chief counsel under the Biden administration.

“Earlier today, I was served official notice from the Attorney General of the United States that I was being removed from my position as the Chief Counsel of ATF and my employment with the Department of Justice terminated,” Hicks posted on her LinkedIn page Thursday.

“Serving as ATF Chief Counsel has been the highest honor of my career and working with the people at ATF and throughout the Department has been a pleasure,” Hicks continued in her post. “I thank my colleagues for their friendship and partnership over the years.” 

Former FBI Director Christopher Wray resigned Jan. 19 — one day before Trump became the 47th president — after the commander in chief signaled he would replace him.

The Senate narrowly voted to approve Patel Thursday, with Sens. Susan Collins (R-Maine) and Lisa Murkowski (R-Alaska) breaking ranks and voting with 47 Democrats against the nominee.

Trump has said that Patel will shake up the bureau and attempt to depoliticize the decision-making after a series of controversies involving either alleged or proven bias against Republicans.

The president has long accused the FBI of politicizing its investigations, including a pair of criminal cases lodged against him for allegedly mishandling classified documents and for challenging the 2020 election results.