Two Pa. lawmakers were in a video critical of Trump. Now, they say, they are under federal investigation.

U.S. Reps. Chrissy Houlahan of Chester County and Chris Deluzio of Allegheny County are among the Democrats who say they are being investigated by President Donald Trump’s administration for appearing in a video that calls on service members not to follow “illegal orders.”

Deluzio, a Navy veteran, said in a Thursday interview that the investigation is “part of a harassment or intimidation campaign against me and my colleagues.”

“The fact that you’ve got members of Congress, all who’ve served the country, being targeted in this way because we stated the law shouldn’t just worry but terrify the American people, and I’m not going to be intimidated or back down in the face of that,” he told The Inquirer.

The Democratic lawmakers who appeared in the Nov. 18 video were contacted late last year by the FBI for interviews. They say they have now been contacted by the U.S. Attorney’s Office for the District of Columbia, a significant escalation in the investigation.

“The six of us are being targeted not because we said something untrue, but because we said something President Trump and Secretary [of Defense Pete] Hegseth didn’t want anyone to hear,” Houlahan, a former Air Force officer, said in a statement Wednesday.

“This investigation is ridiculous on any day but especially so on a day the President is considering launching airstrikes against Iran in retaliation for their crackdown on free speech,” Houlahan said.

The four representatives and two senators, all of whom served in the military or intelligence agencies, said in the video that the Trump administration is “pitting uniformed military and intelligence community professionals against American citizens.”

In response, Trump posted on social media two days later that the lawmakers were engaging in “SEDITIOUS BEHAVIOR, punishable by DEATH!” along with a string of hostile messages toward the lawmakers.

Houlahan said at the time she was disappointed in a lack of support from her GOP colleagues.

U.S. Sen. Elissa Slotkin (D., Mich.), a former CIA analyst who appeared in the video, said Wednesday that representatives for U.S. Attorney Jeanine Pirro, the top federal prosecutor in Washington, had contacted her last week requesting an interview.

Houlahan told reporters that prosecutors want to “sit down” with all the lawmakers who were involved in the video.

U.S. Reps. Jason Crow (D., Colo.), a former paratrooper and Army Ranger, and Maggie Goodlander (D., N.H.), a former intelligence officer, also appeared in the video, as did U.S. Sen. Mark Kelly (D., Ariz.), a former Navy captain.

» READ MORE: What does sedition actually mean? Here’s what to know about Trump’s accusation against Democratic lawmakers.

Kelly filed a lawsuit Monday against the Pentagon and Hegseth over the defense secretary’s attempts to punish Kelly in particular for his participation in the November video.

Kelly claims the Trump administration is violating his constitutional rights to free speech after Hegseth censured the Arizona senator. Hegseth said the Jan. 5 censure was “a necessary process step” to proceedings that could result in a demotion from Kelly’s retired rank of captain and subsequent reduction in retirement pay.

“The First Amendment forbids the government and its officials from punishing disfavored expression or retaliating against protected speech,” Kelly’s lawsuit says. “That prohibition applies with particular force to legislators speaking on matters of public policy.”

Although all six lawmakers served in the military or intelligence agencies, only Kelly served long enough to formally retire from the military, which means the senator still falls under the Pentagon’s jurisdiction. The Pentagon opened its own investigation into Kelly in November after he appeared in the video.

Deluzio said that Trump and Hegseth’s pursuit of Kelly is about more than just the senator.

“They are trying to intimidate retired service members to signal to them that if you speak up and say something that the Trump administration or Pete Hegseth doesn’t like, that they’re going to target your retirement and your pension that you’ve earned after 20 years of service,” he said.

A 2016 video circulated last month of Hegseth citing the same military law the legislators refer to in their video: Don’t follow unlawful orders. As a member of Trump’s administration, Hegseth has pointed to other aspects of military law that emphasize following orders and that say orders should be presumed lawful.

When asked whether he also would sue the Trump administration over how officials have handled the lawmakers’ video, Deluzio said he was “not going to detail my legal strategy in all of this.”

“But I will just be crystal clear that I am not intimidated by what they’re trying to do,” he added.

This article contains information from the Associated Press.