US Senator Mark Kelly has filed a lawsuit against Pentagon chief Pete Hegseth, accusing him of violating the Constitution by seeking to punish the Democratic lawmaker over a video urging US military and intelligence personnel to refuse illegal orders.
The lawsuit, filed on Monday, names Hegseth, the Defence Department, Navy Secretary John Phelan, and the department he leads.
It argues that their actions "violate numerous constitutional guarantees and have no basis in statute" and should be halted.
Kelly, a decorated Navy veteran and former astronaut, has asked the court to declare unlawful a censure letter placed in his military file, as well as any effort to reduce his retirement rank, a move that could affect his pension.
'Undermine military discipline'
Hegseth announced the measures against Kelly last week, accusing the senator and five other lawmakers with military or intelligence backgrounds of releasing what he described as a "reckless and seditious" video intended to undermine military discipline.
In the video, released in November, the lawmakers warned that the Trump administration was "pitting our uniformed military and intelligence community professionals against American citizens."
"Right now, the threats to our constitution aren't just coming from abroad, but from right here at home," they said, adding: "You can refuse illegal orders."
The video did not specify which orders were being referenced, but the Trump administration has faced criticism for its deployment of US forces domestically and abroad.
Within the United States, President Donald Trump has ordered National Guard deployments in several cities, at times against the wishes of local officials, prompting legal challenges.
Overseas, the administration has authorised strikes on alleged drug-smuggling vessels in the Caribbean Sea and eastern Pacific, actions critics have described as extrajudicial killings.
Earlier this month, US forces were also sent into Venezuela, where then-president Nicolas Maduro was captured and taken to the United States to face court proceedings in New York.
