Pat Cipollone spoke to the House Jan. 6 select committee last month.
A federal grand jury has subpoenaed former Trump White House counsel Pat Cipollone in its investigation into the Jan. 6 assault on the U.S. Capitol and efforts to overturn the 2020 election, sources with direct knowledge of the matter told ABC News.
The sources told ABC News that attorneys for Cipollone -- like they did with the House select committee investigating the Jan. 6 attack on the Capitol -- are expected to engage in negotiations around any appearance, while weighing concerns regarding potential claims of executive privilege.
The move to subpoena Cipollone signals an even more dramatic escalation in the Justice Department's investigation of the Jan. 6 attack than previously known, following appearances by senior members of former Vice President Mike Pence's staff before the grand jury two weeks ago.
Officials with the Justice Department declined to comment when contacted by ABC News.
A representative for Cipollone could not be reached for comment.
Last month, Cipollone spoke to the House Jan. 6 select committee for a lengthy closed-door interview, portions of which have been shown during two of the committee's most recent public hearings.
Cipollone spoke to the committee on a number of topics, including how he wanted then-President Donald Trump to do more to quell the riot on the day of the attack, and how Cabinet secretaries contemplated convening a meeting to discuss Trump's decision-making in the wake of the insurrection.
In videotaped testimony before the Jan. 6 committee, Cipollone made it clear that he wanted Trump to intervene sooner while the attack was underway.
"I was pretty clear there needed to be an immediate and forceful response, statement, public statement, that people need to leave the Capitol now," Cipollone said.
Committee members also questioned Cipollone regarding discussions among members of Trump's Cabinet about invoking the 25th Amendment to possibly remove Trump from office in advance of President Joe Biden's inauguration.