As a businessman and presidential candidate, Donald Trump not only valued discretion in his employees, he legally guaranteed it by requiring them to sign lengthy nondisclosure agreements.

One Trump NDA obtained by the Associated Press gagged Trump associates throughout their employment and “at all times thereafter.” It barred them from sharing any insider details in the future and made it clear that they could be sued for disparaging any member of the Trump family, including Barron and Melania Trump or any of Trump’s 10 grandchildren. The NDA applied to everyone from Trump’s top employees in the Trump Organization to campaign volunteers and even the guy who made the famous “Make America Great Again” hats.

But as Trump begins to assemble his new team at the White House and in the Executive Branch, federal employment-law experts say there’s no way for Trump to put a similar gag order in place as president. Yet. And it’s not because he doesn’t want to.

In an interview with The Washington Post in March, Trump told reporter Robert Costa that if he won the White House, he would want to require his new team, who would all be federal employees, to also sign NDAs.

“I don’t know, there could be some kind of a law that you can’t do this,” he said (fact check: true). “But when people are chosen by a man to go into government at high levels and then they leave government and they write a book about a man and say a lot of things that were really guarded and personal, I don’t like that.”

Cheri Cannon, an employment-law specialist in Washington, D.C., said federal employees are required to protect classified information, secret information, personnel decisions, and sensitive contracts in multiple ways as a condition of their employment.

But there’s no way for a President Trump to prevent his political appointees from talking about him and his family, other than showing them the door, she said. Career federal employees have protections that even Trump can’t touch.

“You have a First Amendment right to trash-talk your boss,” Cannon said. “There’s nothing in the world that can stop Joe Blow, Commerce Department employee, from trash-talking the president. You don’t see that a lot, but it could happen.”

Cannon noted that that political appointees all serve without due process “at the pleasure of the president” and can be fired for any reason, including for disparaging Trump. But they can’t be silenced.

“The political appointees are going to lose their jobs,” Cannon said. “Career people can’t lose their jobs, not for speaking their minds.”

Robert Passman, the founding partner at Passman & Kaplan who specializes in federal employment law, said any new NDA for Executive Branch workers would have to be approved by the Office of Personnel Management.

“I don’t think OPM would allow it and I think it would be clearly improper,” Passman said.

He agreed with Cannon that the only thing Trump can really do to encourage political appointees’ silence is to take away their jobs. Trump’s go-to threat to sue somebody won’t be at his disposal as president.

“He can certainly tell them in advance that if they do talk he’ll fire them on the spot, and he can do that,” Passman said. “Otherwise you can’t sue a federal employee for any acts committed within the scope of their employment, except for very rare exceptions.”

Employment-law experts who spoke with The Daily Beast uniformly agreed that Trump may be able to demand his team’s loyalty, but he won’t be able to require their silence, as the law stands today, by doing anything other than firing them, as long as classified information isn’t shared.

But Joanna Friedman, a partner with the Federal Practice Group specializing in federal employment law, said that just as Presidents Clinton and Obama signed executive orders restricting their appointees from lobbying former colleagues for a period of time, Trump could conceivably sign an executive order to add confidentiality and non-disparagement requirements on to new political appointees after they leave the Trump White House.

“He has the power to do it,” she said. “I don’t think it’s a matter of someone signing a contract with Trump. Rather, he’ll use his executive powers to make it law that you have sign this to work for him.” Friedman said a court would have to agree that the new restrictions serve the public interest, which would be a very high bar. But it’s not impossible.

“It is unheard of and it’s never happened,” she said. “But I think we all have learned in the last year that just because it’s unheard of, that doesn’t mean Trump’s not going to make it happen.”