In a sign of just how desperate Donald Trump and his allies have become in their efforts to put together a coherent defense against Democrats’ impeachment inquiry, allies of the president have adopted a novel approach: smear a Purple Heart recipient as an un-American spy. Alexander Vindman, an Iraq veteran and Ukraine expert on the White House National Security Council, is appearing on Capitol Hill Tuesday to offer lawmakers additional testimony about the president’s interactions with Volodymyr Zelensky—as a firsthand witness to Trump’s July 25 phone call with the Ukrainian leader. Faced with that uncomfortable prospect, Trump’s allies went after the messenger, suggesting Vindman is biased because he was born in Ukraine, and even going so far as to theorize that he’s a double-agent.

“Here we have a U.S. national security official who is advising Ukraine, while working inside the White House, apparently against the president’s interest, and usually, they spoke in English,” an incredulous Laura Ingraham said in a panel discussion on her Fox News program Monday evening. “Isn’t that kind of any interesting angle on this story?”

“I find that astounding,” former Department of Justice official John Yoo replied. “Some people might call that espionage.”

It was an incredible charge, but that didn’t stop others on Trump’s favorite network from picking up the line of attack. Discussing the upcoming testimony on Fox & Friends Tuesday morning, Brian Kilmeade also suggested that the Ukrainian-born American war hero was not to be trusted because he “tends to feel simpatico with Ukraine.” Added former congressman, Trump acolyte, and newly-minted CNN commentator Sean Duffy: “It seems very clear that he is incredibly concerned about Ukrainian defense. I don’t know that he’s concerned about American policy.” He added, “We all have an affinity for our homeland. He has an affinity for the Ukraine.”

Vindman was born in Ukraine, but came to the U.S. as a refugee at three. In the subsequent years, he served multiple tours of duty as an army lieutenant, including in Iraq, where he was injured by a roadside bomb and awarded the Purple Heart. He joined the National Security Council under Trump in 2018 as a Harvard-educated Ukraine expert. In an opening statement to House investigators, Vindman will testify that he twice reported concerns about the conduct of the president and his allies relating to Ukraine. He became concerned earlier this year about “outside influencers” working on Ukraine policy that undercut government policy, he said, and reported to the NSC’s lead counsel alarming statements made by Gordon Sondland, Trump’s ambassador to the European Union. Vindman was among the staff listening in on Trump’s call with Zelensky, after which he again reported his concerns about Trump’s conduct on the call to the NSC lead counsel. “I did not think it was proper to demand that a foreign government investigate a U.S. citizen, and I was worried about the implications for the U.S. government’s support of Ukraine,” he wrote in his prepared remarks.