The subpoena seeking a deposition from Pat Cipollone followed dramatic public testimony on Tuesday from a former White House aide, who told the panel that Cipollone had warned her they could face “every crime imaginable” if Trump went to the Capitol on January 6, 2021, after delivering a fiery rally speech to his supporters.

“The select committee’s investigation has revealed evidence that Cipollone repeatedly raised legal and other concerns about President Trump’s activities on January 6th and in the days that preceded,” the panel said on Wednesday.

“Any concerns Mr Cipollone has about the institutional prerogatives of the office he previously held are clearly outweighed by the need for his testimony,” the committee said.

Cipollone could not be reached immediately for comment.

Cassidy Hutchinson, an aide to Trump’s White House Chief of Staff Mark Meadows, told the committee on Tuesday that Trump wanted to leave the rally for the Capitol and that he grabbed the steering wheel of the presidential SUV when he learned the Secret Service would not drive him to the Capitol, where thousands of his supporters rioted.

“We’re going to get charged with every crime imaginable,” Hutchinson said Cipollone told her if Trump were to go to the Capitol on January 6.

“‘We need to make sure that this doesn’t happen, this would be a really terrible idea for us. We have serious legal concerns if we go up to the Capitol that day,’” Cipollone said, Hutchinson testified.

But the probe faced questions on Wednesday about what steps it had taken to corroborate Hutchinson’s account of Trump’s having struggled with Secret Service agents.

Hutchinson testified that Tony Ornato, a senior Secret Service official, told her that Trump, a Republican, had struggled with agents after giving a fiery speech to his supporters outside the White House that morning in which he repeatedly falsely blamed widespread fraud for his election loss to Democrat Joe Biden.

US media outlets, citing Secret Service sources, said the head of Trump’s security detail, Robert Engel, and the driver of the car were prepared to challenge Hutchinson’s testimony that Trump had tried to grab the steering wheel.

Trump on Tuesday denied having grabbed the wheel.

An aide to the US House of Representatives committee declined to answer questions about whether it already had interviewed Secret Service agents or other officials with firsthand knowledge of the incident Hutchinson described.

“Ms Hutchinson stands by all of the testimony she provided yesterday, under oath, to the Select Committee to Investigate the January 6th Attack on the United States Capitol,” her lawyers Jody Hunt and William Jordan said in a statement.

A Secret Service spokesman said the committee had not sought to confirm details of Hutchinson’s testimony before the hearing, which was scheduled unusually quickly.

The riot was an attempt to stop Congress, with vice-president Mike Pence presiding, from certifying Biden’s election.

Supporters of Trump have not challenged other revelations in Hutchinson’s testimony. These included Trump’s knowledge – even approval – of his supporters’ walking around Washington heavily armed on January 6 and that he had no qualms about rioters’ urging that Pence be hanged.

Hutchinson also testified that Trump was known for angry outbursts in the White House that left food being splayed onto walls and dishes upended.

-AAP