Astonishing footage of House Speaker Nancy Pelosi threatening to “punch out” Donald Trump has emerged from the US Capitol, hours before a mob incited by him stormed the building in January 2021.

The footage, taken by Ms Pelosi’s daughter Alexandra and aired on CNN on Friday (Australian time), shows multiple congressional leaders in the hours before the January 6 uprising.

It captures Ms Pelosi talking to her staff as Mr Trump spoke at the rally that preceded the Capitol riot. She tells them the then-US president should not come to the Capitol as Congress prepares to certify Joe Biden’s victory in the 2020 presidential election.

“If he comes, I’m gonna punch him out,” Ms Pelosi said.

“I’ve been waiting for this, for trespassing on the Capitol grounds. I’m gonna punch him out, and I’m gonna go to jail and I’m gonna be happy.”

Tweet from @Acyn

The film emerged hours after the US House of Representatives committee investigating the attack on the US Capitol voted to subpoena Mr Trump, an action that could eventually result in the former president going to jail if he fails to comply.

The House select committee’s seven Democratic and two Republican members voted 9-0 in favour early on Friday (Australian time) of issuing a subpoena for Mr Trump to provide documents and testimony under oath in connection with the January 6 2021 riots.

“He is the one person at the centre of the story of what happened on January 6. So we want to hear from him,” the panel’s Democratic chairman, Representative Bennie Thompson, said.

The vote came after the committee spent more than two hours making its case – via statements from members, documents, and recorded testimony – that Mr Trump planned to deny his 2020 election defeat in advance, failed to call off the thousands of supporters who stormed the Capitol, and followed through with his claims the election was stolen even as close advisers told him he had lost.

Federal law says that failure to comply with a congressional subpoena for testimony or documents is a misdemeanour, punishable by one to 12 months imprisonment.

If the select committee recommends a subpoena that is ignored, the full House must vote on whether to make a referral to the Department of Justice. It has the authority to decide whether to bring charges.

However, Mr Trump was – perhaps predictably – scornful of Friday’s vote, condemning it as a publicity stunt.

“Why didn’t the Unselect Committee ask me to testify months ago?” he posted on his Truth Social platform shortly after the vote.

“Why did they wait until the very end, the final moments of their last meeting? Because the Committee is a total ‘BUST’ that has only served to further divide our Country which, by the way, is doing very badly – A laughing stock all over the World?”

The House select committee has been investigating the attack on the Capitol, which left more than 140 police officers injured and led to several deaths, for more than a year, interviewing more than 1000 witnesses.

Earlier, the committee was told Ms Pelosi, Senate Majority Leader Chuck Schumer and other top lawmakers urgently dialled military officials and White House staff seeking help during the assault on the Capitol by Trump supporters, video shown on Thursday revealed.

At what is likely its last hearing on the deadly attack, the House of Representatives Select Committee aired the previously unseen video that showed the fear gripping the Capitol as rioters stormed the building.

It showed Ms Pelosi and Mr Schumer, top Senate Republican Mitch McConnell, and Republican Senator John Thune calling the Department of Defence asking for military backup to help clear the Capitol complex.

Ms Pelosi and Mr Schumer also called acting attorney-general Jeffrey Rosen.

Rioters were breaking windows and ransacking their offices “and all the rest of that – that’s nothing”, Ms Pelosi said on the call, the footage showed.

“The concerns we have about personal safety just transcend everything. But the fact is on any given day they’re breaking the law in many different ways. And quite frankly, much of it at the instigation of the president of the United States.”

“Why don’t you get the president to tell them to leave the Capitol, Mr attorney-general, in your law enforcement responsibility?” Mr Schumer said on the call.

“A public statement: They should all leave.”

The footage also showed Ms Pelosi and top House Democrats being told that members of the House were pulling on gas masks. Upon hearing this, Ms Pelosi silently looked at House Majority Whip Jim Clyburn.

“Can you believe it?” she said, turning to someone off screen.

She was also shown talking to Ralph Northam, then governor of Virginia, asking what military aid his state was able to send and whether he was able to send police without permission from the federal government.

In the video, Ms Pelosi said she planned to call Larry Hogan, governor of Maryland, about sending the National Guard from his state. Maryland and Virginia border Washington, DC.

The hearing room fell silent while the footage was being shown. Many of those present – including reporters and congressional staff – were in the Capitol during the attack.

US top court rejects Trump documents plea

In another blow to Mr Trump on Friday, the US Supreme Court rejected his plea to step into the legal fight over the FBI search of his Florida estate.

Mr Trump’s lawyers had asked the justices to overturn a lower court ruling and permit an independent arbiter, or special master, to review the roughly 100 documents with classified markings that were taken in the August 8 search of Mar-a-Lago.

A three-judge panel from the Atlanta-based US Court of Appeals for the 11th Circuit last month limited the special master’s review to the much larger tranche of non-classified documents.

The judges, including two Trump appointees, sided with the Justice Department, which had argued there was no legal basis for the special master to conduct his own review of the classified records.

The FBI says it seized roughly 11,000 documents, including about 100 with classification markings, during its search.

-with AAP