House Speaker Nancy Pelosi on Thursday accused Attorney General William Barr of lying to Congress, an action the top Democrat condemned as an outright crime by the nation’s top law enforcement official.

“What is deadly serious about it is the attorney general of the United States of America was not telling the truth to the Congress of the United States,” she told reporters at her weekly press conference. “That’s a crime.”

When asked if Barr should be jailed over his testimony, Pelosi said that lawmakers on the House Judiciary Committee would soon be announcing how they intended to move forward.

Pelosi: "What is deadly serious about it is the attorney general of the United States of America was not telling the truth to the Congress of the United States. That's a crime." https://t.co/RMrE0UXKqQ pic.twitter.com/ejUYU0sfQH — POLITICO (@politico) May 2, 2019

The remarks, which make Pelosi the highest-ranking Democrat to accuse Barr of lying to Congress, follow the explosive revelation this week of a letter Robert Mueller had written to Barr in late March, which expressed frustration over how the attorney general had characterized the findings of the special counsel’s investigation in a 4-page summary released to the public. Despite direct knowledge of Mueller’s concerns, Barr last month told Congress that he hadn’t been aware of them, testimony Democrats now say should lead to Barr’s resignation. Here’s the April 9th exchange Pelosi and Democrats are referring to, via PolitiFact:

Rep. Charlie Crist (D-Fla.): “Reports have emerged recently, general, that members of the special counsel’s team are frustrated at some level with the limited information included in your March 24 letter, that it does not adequately or accurately, necessarily, portray the report’s findings. Do you know what they’re referencing with that?” William Barr: “No, I don’t. I think, I suspect that they probably wanted more put out. But in my view, I was not interested in putting out summaries or trying to summarize because I think any summary — regardless of who prepares it — not only runs the risk of being underinclusive or overinclusive but also would trigger a lot of discussion and analysis that really should await everything coming out at once.”

One day after Mueller’s letter was reported, Barr made several misleading statements about the Mueller investigation to the Senate Judiciary Committee. He refused to appear before the House Judiciary Committee on Thursday because he objected to the format of the hearing, where he was to be questioned by staff lawyers. Committee chairman Rep. Jerrold Nadler is now considering subpoenaing Barr over the no-show.