(Newser) – President Trump is continuing to fight back against the impeachment inquiry by calling for his critics to be impeached. After calling for Mitt Romney's impeachment on Saturday—and continuing to hammer him Sunday—the president called for the impeachment of House Speaker Nancy Pelosi on Sunday night, accusing her of treason. "She knew of all of the many Shifty Adam Schiff lies and massive frauds perpetrated upon Congress and the American people," Trump tweeted. "This makes Nervous Nancy every bit as guilty as Liddle’ Adam Schiff for High Crimes and Misdemeanors, and even Treason. I guess that means that they, along with all of those that evilly 'Colluded' with them, must all be immediately Impeached!"

Member of Congress can't be impeached, but they can be expelled with a two-thirds vote in the House or Senate. Trump's remarks came after reports that a second whistleblower had come forward with firsthand knowledge of the phone call to Ukraine's president that sparked the complaint that led to the impeachment inquiry, the BBC reports. Voice of America reports that the inquiry will move forward this week, with key figures including Marie Yovanovitch, the former US ambassador to Ukraine, scheduled to testify before House committees. House lawmakers are also waiting for a response to their subpoenas for information from the White House, State Department, and Trump lawyer Rudy Giuliani. (Read more Trump impeachment stories.)

