The Democratic lawmakers who urged servicemembers to ignore illegal orders are now being asked to sit for interviews with the FBI, they said in a statement on Tuesday. President Trump has been calling for those members of Congress to be jailed for the last several days. 

Last week, six members of the legislative branch — two senators and four House members, all of whom are veterans of the military or the CIA — told servicemembers in a direct-to-camera video that they have a responsibility to refuse any order that they believe is illegal. 

They did not explicitly name an illegal order which Mr. Trump may have given this year. Rather, it was more of a general warning to servicemembers about not breaking the law. 

On Tuesday, the four House members who were in the video said in a statement that the House sergeant at arms had been contacted by the FBI about those lawmakers sitting for interviews with law enforcement. In response, they said they will not be bullied by the administration, and implied that they would not voluntarily interview with the agency. 

“President Trump is using the FBI as a tool to intimidate and harass Members of Congress,” the four House members said in a joint statement, adding that the Senate sergeant at arms had been contacted, as well. 

“No amount of intimidation or harassment will ever stop us from doing our jobs and honoring our Constitution,” the House members added. “We swore an oath to support and defend the Constitution of the United States. That oath lasts a lifetime, and we intend to keep it. We will not be bullied. We will never give up the ship.”

The two senators in the video — Senator Mark Kelly, a retired Navy captain, and Senator Elissa Slotkin, a retired CIA agent — have also pushed back forcefully against the president’s threats. Mr. Kelly is now under investigation by the Defense Department for his comments in the video, which could result in him being recalled to active duty in order to face a court martial. 

“In accordance with the Uniform Code of Military Justice … and other applicable regulations, a thorough review of these allegations has been initiated to determine further actions, which may include recall to active duty for court-martial proceedings or administrative measures,” the Defense Department said in a statement on Monday. 

Defense Secretary Pete Hegseth began referring to the lawmakers in the video as the “Seditious Six” after Mr. Trump accused them of sedition in a series of Truth Social posts over the weekend. 

“In the military, vague rhetoric and ambiguity undermines trust, creates hesitation in the chain of command, and erodes cohesion,” Mr. Hegseth said on X on Tuesday, saying that the military does not need “political actors injecting doubt into an already clear chain of command.”

Democrats and civil libertarians alike have been quick to denounce the threats and intimidation against the members of Congress in the video. A former lawmaker, Congressman Justin Amash, who left the GOP to become a Libertarian House member, said that Mr. Hegseth should be impeached and removed from his post. 

“Even if it were politically motivated, it would not be unlawful to make such a video. His effort to mislead millions of Americans about the Constitution, the freedom of speech, and the basic operation of law is abhorrent,” Mr. Amash wrote of the Defense Secretary on Tuesday.