The House Permanent Select Committee on Intelligence on Thursday subpoenaed retired Lt. Gen. Michael Flynn and former Trump Deputy Campaign Manager Rick Gates for documents and testimony.

Rep. Adam Schiff (D-CA), the panel’s chairman, claims the pair have been uncooperative in Congress’s “oversight” investigation into Russian interference in the 2016 presidential election.

“As part of our oversight work, the House Intelligence Committee is continuing to examine the deep counterintelligence concerns raised in Special Counsel Mueller’s report, and that requires speaking directly with the fact witnesses,” Schiff said in a statement. “Both Michael Flynn and Rick Gates were critical witnesses for Special Counsel Mueller’s investigation, but so far have refused to cooperate fully with Congress.”

The California Democrat continued: “That’s simply unacceptable. The American people, and the Congress, deserve to hear directly from these two critical witnesses. We hope these witnesses come to recognize their cooperation as being with the United States, not merely the Department of Justice.”

Flynn and Gates are to turn over documents to the committee by June 26th and sit for an interview, under oath, on July 10th, the subpoena states.

Flynn admitted to making false statements to the FBI regarding conversations he shared with then-Russian Ambassador Sergey Kislyak in 2017, while Gates pleaded guilty to false statements and conspiracy charges related to political consulting efforts he and onetime Trump campaign chairman Paul Manafort undertook for Ukraine. The trio was charged as part of special counsel Robert Mueller’s investigation into now-debunked collusion between the 2016 Trump campaign and Russia.

The development comes a day after Flynn, who served as President Donald Trump’s first national security advisor, hired seasoned lawyer Sidney Powell as his new counsel as he awaits sentencing.

The former Assistant U.S. Attorney is an outspoken critic of the Mueller probe and has called Andrew Weissmann, often referred to as the special counsel’s “pit bull,” the “poster boy for prosecutorial misconduct.”

The move came after court filings revealed last week that Flynn terminated his lawyers Stephen Anthony and Robert Kelner of Covington & Burling LLP, as his counsel.

President Trump praised Powell’s hiring on social media Thursday morning, calling her a “great lawyer.”

“General Michael Flynn, the 33 year war hero who has served with distinction, has not retained a good lawyer, he has retained a GREAT LAWYER, Sidney Powell. Best Wishes and Good Luck to them both!” the president tweeted.