The FBI has requested interviews with six Democratic lawmakers who appeared in a social media video urging members of the United States military to “defy illegal orders”, according to the legislators.

The statements on Tuesday came a day after the Pentagon said it was reviewing Senator Mark Kelly, a US Navy veteran and one of the six lawmakers, over potential violations of military law.

President Donald Trump has previously accused the lawmakers of sedition and said in a social media post that the crime is “punishable by DEATH”.

All six of the Democratic lawmakers in the video have served in the military or the intelligence community.

Senator Elissa Slotkin of Michigan, one of the six in the video, told reporters on Tuesday that “the counterterrorism division at the FBI sent a note to the members of Congress, saying they are opening what appears to be an inquiry against the six of us”.

Slotkin called it a “scare tactic” by Trump.

“Whether you agree with the video or don’t agree with the video, the question to me is: Is this the appropriate response for a president of the United States to go after and seek to weaponise the federal government against those he disagrees with?” said Slotkin.

‘Intimidation, harassment’

The lawmakers said their video statements accurately reflected US law. American troops swear an oath to the US Constitution, not the president, and under military rules must follow “any lawful general order or regulation”.

The other Democrats who appeared in the video that was released last week include US Representatives Jason Crow, Maggie Goodlander, Chris Deluzio and Chrissy Houlahan, all military veterans.

“President Trump is using the FBI as a tool to intimidate and harass Members of Congress,” the four House Democrats said in a joint statement. “Yesterday, the FBI contacted the House and Senate Sergeants-at-Arms requesting interviews.”

They added that “no amount of intimidation or harassment will ever stop us from doing our jobs and honoring our Constitution”.

There was no immediate comment from Senator Kelly.

The Reuters news agency, citing a Department of Justice official, reported that the FBI interviews were to determine “if there’s any wrongdoing, and then go from there”.

The FBI is headed by Trump appointee Kash Patel.

Defense Secretary Pete Hegseth, in a memo made public on Tuesday, referred Kelly to the secretary of the Navy for “potentially unlawful comments” made in the video last week. Hegseth said he wanted a brief on the outcome of the review by December 10.

Together, the inquiries by the FBI and the Pentagon mark an extraordinary escalation for federal law enforcement and military institutions that traditionally steer clear of partisan clashes. They also underscore the administration’s willingness to push legal limits against its critics, even when they are sitting members of Congress.

‘Frivolous investigation’

The inquiries have prompted criticism from Republicans, too.

Senator Lisa Murkowski of Alaska slammed both inquiries on social media, saying that accusing the lawmakers “of treason and sedition for rightfully pointing out that service members can refuse illegal orders is reckless and flat-out wrong”.

“The Department of Defense and FBI surely have more important priorities than this frivolous investigation,” wrote Murkowski.

The lawmakers said they had no further information, and the FBI has not made clear on what basis they were seeking the interviews.

Patel, the FBI director, in an interview with a journalist, described the bureau’s investigation as an “ongoing matter” in explaining why he could not discuss details.

Asked for his reaction to the video, Patel said, “What goes through my head is the same thing that goes through my head in any case: Is there a lawful predicate to open up an inquiry and investigation, or is there not? And that decision will be made by the career agents and analysts here at the FBI.”

In the video, lawmakers said they needed troops to “stand up for our laws … our Constitution”. Kelly, who was a fighter pilot before becoming an astronaut and then retiring at the rank of captain, told troops that “you can refuse illegal orders”.

The lawmakers did not mention specific circumstances in the video.

At an event in Michigan on Tuesday, Slotkin pointed to the Trump administration ordering the military to blow up small boats in the Caribbean Sea and eastern Pacific Ocean, which officials accuse of ferrying drugs, and continued attempts at deploying National Guard troops into US cities despite some legal setbacks.

“It wasn’t that there was any one incident; it was the sheer number of people coming to us and saying, ‘I’m worried. I am being sent to Washington’ or ‘I’m being sent to LA or Chicago, North Carolina now, and I’m concerned I’m going to be asked to do something that I don’t know if I should do,’” said Slotkin. “So that’s where it came from.”

Troops, especially uniformed commanders, do have specific obligations to reject orders that are unlawful, if they make that determination.

Broad legal precedence also holds that just following orders, colloquially known as the “Nuremberg defence”, as it was used unsuccessfully by senior Nazi officials to justify their actions under Adolf Hitler, does not absolve troops of responsibility.