(TNS) — Cliff Sims is turning the tables.

The former White House communications aide filed a lawsuit against President Donald Trump on Monday, alleging the commander-in-chief is trying to infringe on his free speech rights by issuing a legal threat over his tell-all book about the administration.

Attorney Mark Zaid, who represents Sims, said the president is barred by the First Amendment from trying in his official capacity to silence the ex-White House staffer for releasing “Team of Vipers” last month.

“Cliff is a major Trump supporter and only pursued this action because he was forced to defend himself,” Zaid told the New York Daily News.

The Trump re-election campaign filed a private arbitration suit against Sims on Jan. 31 over his book allegedly violating a non-disclosure agreement he signed upon joining the 2016 presidential bid.

But Zaid, citing “sources,” charged the arbitration was filed on Trump’s orders, thereby violating Sims’ First Amendment protections, since the U.S. government — in this case, the president — is prohibited by the Constitution from silencing federal employees once they leave office, unless it pertains to classified information.

In that sense, Zaid said, Trump is using his campaign as a “cutout” for revenge.

“It’s our understanding from sources that the president was consulted and instructed the campaign should proceed with the arbitration,” Zaid said.

Moreover, Zaid argued the timing of a particular Trump tweet shows the campaign was acting on the president’s directives.

“A low level staffer that I hardly knew named Cliff Sims wrote yet another boring book based on made up stories and fiction,” Trump tweeted on Jan. 29. “He pretended to be an insider when in fact he was nothing more than a gofer. He signed a non-disclosure agreement. He is a mess!”

About 20 minutes later, Trump campaign chief operating officer Michael Glassner tweeted the campaign was “preparing to file suit against Cliff Sims.”

A White House spokesman did not immediately return a request for comment.