Washington — Democratic Sen. Mark Kelly of Arizona filed a civil lawsuit against Defense Secretary Pete Hegseth on Monday seeking to block the Pentagon’s efforts to downgrade his retirement rank and pay, which he claims amounts to unconstitutional retaliation against him.

In a 46-page complaint, Kelly, a retired Navy captain, argued that he is the target of “extreme rhetoric and punitive retribution” by the Trump administration over a video in which he and other lawmakers urged members of the military to “refuse illegal orders.” Kelly asked a federal judge to set aside Hegseth’s recent moves and block the enforcement of any punishment against him.

The Arizona Democratic senator alleged that he was punished for protected speech and said administration officials retaliated against him in violation of the First Amendment. Kelly also argued that his criticisms of Hegseth are at the core of the Constitution’s Speech or Debate Clause, which provides immunity to lawmakers from criminal prosecutions or civil lawsuits that stem from legislative acts.

“It appears that never in our nation’s history has the Executive Branch imposed military sanctions on a Member of Congress for engaging in disfavored political speech,” Kelly’s legal team wrote in the complaint. “Allowing that unprecedented step here would invert the constitutional structure by subordinating the Legislative Branch to executive discipline and chilling congressional oversight of the armed forces.” 

They said Kelly’s public statements and legislative acts in response to the Trump administration’s actions regarding the military are “significant matters of public concern” that fit within the First Amendment’s protections and his oversight responsibilities as a senator. The senator’s lawyers added that they believe there is no legal basis to take action against him based on “post-retirement political speech.”

Kelly said in a statement that Hegseth’s efforts to punish him leave military veterans at risk of seeing their rank and pay downgraded years after they retire for making comments that he or other defense secretaries dislike.

“His unconstitutional crusade against me sends a chilling message to every retired member of the military: if you speak out and say something that the President or Secretary of Defense doesn’t like, you will be censured, threatened with demotion, or even prosecuted,” Kelly said.

Kelly and his colleagues came under fierce criticism by the Trump administration after they posted the video in November. The video was published amid the military buildup around Venezuela and strikes against alleged drug boats, and featured five other Democratic lawmakers who served in the U.S. military or in the intelligence community. They have not faced any adverse action from the Defense Department as they do not draw retirement pay from the U.S. military. 

President Trump and Hegseth lambasted the lawmakers for the comments, claiming that their statements amounted to “sedition” and “treason.”

Hegseth claimed Kelly’s statements “undermined the chain of command” and constituted “conduct unbecoming an officer.” The Pentagon announced it was conducting a review of misconduct allegations against Kelly to determine whether he should be recalled to active duty to face court-martial proceedings.

The Defense Department said in December it was “escalating” its review into a command investigation.

Hegseth announced last week that the Pentagon had “initiated retirement grade determination proceedings” that could result in a “reduction in his retired grade” and “a corresponding reduction in retired pay.” Hegseth also said he issued a formal letter to censure Kelly, citing his “reckless misconduct.”

“This Censure is a necessary process step, and will be placed in Captain Kelly’s official and permanent military personnel file,” Hegseth added. 

Under federal law, retired U.S. military members can receive non-judicial punishments or even be charged, court-martialed and punished under the Uniform Code of Military Justice, the system of rules and regulations established by Congress governing the military.