From the Committee's press release:

Today, the White House and Department of Justice ordered Rob Porter, former White House staff secretary and Rick Dearborn, former White House Deputy chief of staff for policy implementation, to defy subpoenas issued for their testimony before the House Judiciary Committee as part of its impeachment investigation. The White House also placed unprecedented limitations on the testimony of Corey Lewandowski, President Trump’s former campaign manager. House Judiciary Committee Chairman Jerrold Nadler (D-NY) issued the following statement in response: “This is a shocking and dangerous assertion of executive privilege and absolute immunity. The President would have us believe that he can willfully engage in criminal activity and prevent witnesses from testifying before Congress--even if they did not actually work for him or his administration. If he were to prevail in this cover-up while the Judiciary Committee is considering whether to recommend articles of impeachment, he would upend the separation of powers as envisioned by our founders. “No one is above the law. The House Judiciary Committee will continue our investigation of the President’s crimes, corruption and cover-up and get to the truth for the American people.” Background: Corey Lewandowski served as Donald Trump’s campaign manager from January 2015 to June 2016. (Mueller Report, Appendix B, B-6). He remained in close contact with the President thereafter.

• Trump asked Lewandowski to have Jeff Sessions limit the Mueller investigation. As the Report states, “[o]n June 19, 2017, the President met one-on-one in the Oval Office with his former campaign manager Corey Lewandowski, a trusted advisor outside the government, and dictated a message for Lewandowski to deliver to Sessions. The message said that Sessions should publicly announce that, notwithstanding his recusal from the Russia investigation, the investigation was ‘very unfair’ to the President, the President had done nothing wrong, and Sessions planned to meet with the Special Counsel and ‘let [him] move forward with investigating election meddling for future elections.’ Lewandowski said he understood what the President wanted Sessions to do.” (Report, p. 5, Vol. II)

• Trump asked Lewandowski a second time to have Sessions limit Mueller. According to the Report, “in another private meeting with Lewandowski on July 19, 2017, the President asked about the status of his message for Sessions to limit the Special Counsel investigation to future election interference. Lewandowski told the President that the message would be delivered soon.” (Report, p. 5, Vol. II)The Report says that “Lewandowski recalled that the President told him that if Sessions did not meet with him, Lewandowski should tell Sessions he was fired.” (Report, p. 93, Vol. II)

Rick Dearborn served as White House Deputy chief of staff for policy. Dearborn previously served as chief of staff to then-Senator Jeff Sessions before joining the Trump administration. (Report, Appendix B, B-3; Report, p. 105, Vol. I)

• Corey Lewandowski asked Dearborn to deliver the message to Sessions limiting Mueller’s investigation. As the Report states, “[i]mmediately following the meeting with the President, Lewandowski saw Dearborn in the anteroom outside the Oval Office and gave him a typewritten version of the message the President had dictated to be delivered to Sessions. Lewandowski told Dearborn that the notes were the message they had discussed, but Dearborn did not recall whether Lewandowski said the message was from the President. The message “definitely raised an eyebrow” for Dearborn, and he recalled not wanting to ask where it came from or think further about doing anything with it. Dearborn also said that being asked to serve as a messenger to Sessions made him uncomfortable. He recalled later telling Lewandowski that he had handled the situation, but he did not actually follow through with delivering the message to Sessions, and he did not keep a copy of the typewritten notes Lewandowski had given him.” (Report, p. 93, Vol. II)

Rob Porter served as White House staff secretary from January 2017 to February 2018 (Report, Appendix B, B-8).

• Trump directed Porter to tell Don McGahn to create a false record suggesting that Trump never ordered McGahn to fire Mueller. “The President told Porter that the article was ‘bullshit’ and he had not sought to terminate the Special Counsel. The President said that McGahn leaked to the media to make himself look good. The President then directed Porter to tell McGahn to create a record to make clear that the President never directed McGahn to fire the Special Counsel. Porter thought the matter should be handled by the White House communications office, but the President said he wanted McGahn to write a letter to the file ‘for our records’ and wanted something beyond a press statement to demonstrate that the reporting was inaccurate.” (Report, p. 115, Vol. II)

• Porter told McGahn that Trump wanted him to create a false record and that the President said he would fire McGahn if he did not do it. The Report says that on February 5, 2018, “Porter spoke to McGahn to deliver the President's message. Porter told McGahn that he had to write a letter to dispute that he was ever ordered to terminate the Special Counsel. McGahn shrugged off the request, explaining that the media reports were true. McGahn told Porter that the President had been insistent on firing the Special Counsel and that McGahn had planned to resign rather than carry out the order, although he had not personally told the President he intended to quit. Porter told McGahn that the President suggested that McGahn would be fired if he did not write the letter.” (Report, p. 116, Vol. II)

The White House letter blocking Rick Dearborn and Rob Porter is available here.The White House letter limiting Lewandowski is available here.The DOJ letter regarding Rob Porter is available here.