The House’s January 6th committee asked Ivanka Trump on Thursday to voluntarily cooperate with its inquiry into the Capitol attack, the clearest sign that investigators are zeroing in on the former president and his family.

In a letter addressed to Ivanka Trump explaining why they seek her cooperation, the committee chairman, Rep. Bennie Thompson (D-MS), revealed testimony previously collected from Keith Kellogg, a retired lieutenant general who was Vice President Mike Pence’s national security adviser. Kellogg and Ivanka were with the former president on the morning of January 6th as he sought to convince Pence on a phone call that he should impede the certification of the 2020 presidential election.

CNN explains:

In sworn testimony to the committee, Kellogg confirmed that the former President told Pence, “You’re not tough enough to make the call.”

Kellogg also corroborated an account of the phone call where Trump claimed that if Pence did not do what he was asking, he had selected the wrong running mate.

“Mike, it’s not right. You can do this. I’m counting on you to do it. If you don’t do it, I picked the wrong man four years ago. You’re going to wimp out,” the transcript of the interview read that Kellogg confirmed.

Kellogg also revealed in his testimony to the committee that after the phone call ended, Ivanka Trump turned to him and said, “Mike Pence is a good man” to which Kellogg affirmed, “Yes, he is.”

The letter also noted that after senior White House aides failed to convince the former president to release a statement condemning the Capitol riot, they asked Ivanka to intercede.

POLITICO reports:

“He didn’t say yes to Mark Meadows, Kayleigh McEnanay or Keith Kellogg, but he might say yes to his daughter?” a committee investigator asked of Kellogg, a top Trump White House official, during a recent interview, according to a testimony transcript published by the panel.

“Exactly right,” Kellogg replied, according to a transcript of the exchange.

The New York Times adds:

The letter also revealed that an unidentified member of the House Freedom Caucus who was aware of Mr. Trump’s plans warned Mark Meadows, the former White House chief of staff, in a text message that “if POTUS allows this to occur … we’re driving a stake in the heart of the federal republic.”

The letter is the latest step that the committee has taken to obtain information from Mr. Trump’s family about the events that led up to the Capitol riot. The panel has also sought logs of phone calls and text messages between the former president’s son Eric Trump and Kimberly Guilfoyle, the girlfriend of another son, Donald Trump Jr., according to CNN.

A spokesperson for Ivanka Trump released a statement shortly after the committee’s letter was released: “As the Committee already knows, Ivanka did not speak at the January 6 rally,” the statement said. “As she publicly stated that day at 3:15pm, ‘any security breach or disrespect to our law enforcement is unacceptable. The violence must stop immediately. Please be peaceful.’”