It is unclear whether and under what conditions the Acting Attorney General would appear Friday before the House Judiciary Committee.
"Arguably you sold your country out," the judge tells the ex-national security adviser, raising the prospect of prison for lying to the FBI.
With a number of probes moving closer to the Oval Office, the president and his attorney unleash a fresh series of attacks.
A prison stint is possible if it is proved that the president directed illegal hush-money payments to women, House leaders say.
The special counsel makes the stunning allegation with details to come later. It could mean more jail time or charges for a key witness.
By cutting a deal in a case related to his Ukrainian political consulting work, the former Trump campaign manager avoids a second trial. The charges do not relate to Russian interference in the 2016 presidential election.
President Trump says McGahn will step down after the Senate vote on Supreme Court nominee Brett Kavanaugh. McGahn has played a major role in Trump's overhaul of the federal judiciary with conservative judges.
The president, in a series of angry tweets, denounces a New York Times story that White House counsel Don McGahn has been cooperating with Robert Mueller's team investigating Russian election meddling.
The former CIA director says that while he'll fight on behalf of his onetime colleagues, it's up to Congress to put aside politics and step in.