The struggle of Nancy Pelosi, the speaker of the House of Representatives, to preserve American democracy in the dramatic hours of the January 6 attack are captured in a new documentary film shot by her daughter.

Pelosi is seen watching on TV Donald Trump’s incendiary speech to his supporters, getting rushed out of the US Capitol building and making calls to Vice-President Mike Pence and other officials from the Fort McNair military base, where congressional leaders took refuge from the mob.

Despite the chaos and confusion, she is immediately clear that Trump is responsible for instigating what she describes as an “insurrection”.

The blow-by-blow reconstruction of the assault on democracy is contained in Pelosi in the House, produced and directed by the speaker’s daughter, film-maker Alexandra Pelosi, broadcast on HBO on Tuesday. Some of the behind-the-scenes footage was seen in edited form during the House January 6 committee hearings.

Early in the day Pelosi is in her office, wearing a face mask and adjusting her hair, as three TV screens show Trump whipping up his supporters at the Ellipse and vowing never to concede the 2020 presidential election. She tells her staff with a laugh: “Tell him if he comes here, we’re going to the White House.”

Watching through a window, Alexandra’s teenage son, Paul, spots a flag-waving mob gathering ominously outside the US Capitol. Pelosi’s chief of staff, Terri McCullough, reports that the Secret Service have dissuaded Trump from coming to the Capitol because they would not have the resources to protect him.

Pelosi replies defiantly: “If he comes, I’m going to punch him out. I’ve been waiting for this. For trespassing on the Capitol grounds, I’m going to punch him out and I’m going to go to jail, and I’m going to be happy.”

Members of Congress adjourn to consider objections to the 2020 election results. A car has “Trump” and “Pelosi is Satan” signs on its windscreen. The chanting, horn-blowing mob attacks police, smashes windows and force its way into the building, shouting: “This is our house!”

Pelosi escapes with just two minutes to spare. At 2.15pm she is escorted to safety down a staircase. She asks: “Are they calling the national guard?” A woman replies: “Yes. Yes, ma’am.”

Hastening through a tunnel, she asks: “Did you reach McConnell?” – a reference to the then Senate majority leader, Mitch McConnell. Someone says: “We did.” Pelosi: “And will they call the national guard?” Reply: “That’s correct.”

Upstairs, the rioters are demanding to know where votes are counted. Walking through another corridor with aides around her, Pelosi evidently realises what a perilous moment this is for democracy. She says: “If they stop the proceedings, they will have succeeded in stopping the validation of the president of the United States. If they stop the proceedings, we will have totally failed.”

She is then seen on a phone, telling an unidentified person: “We have got to finish the proceedings or else they will have a complete victory.”

Both Pelosi and her daughter climb into the back of a black SUV so they can be taken to safety. Upstairs, her office is being ransacked by Trump supporters. One thinks he has found Pelosi’s laptop. Another asks: “You want Nancy’s pink boxing gloves?” Someone shouts with primal rage: “Fuck Nancy Pelosi!”

Sitting in the moving vehicle, the speaker is livid at the disruption of Congress’s sacred duty. “So what’s the prospect? We’re gonna stay here all day, for the rest of our lives, or what? We’re here until what, until the national guard decides to come and get rid of these people?”

By now the insurrectionists are inside the Senate chamber. One demands: “Do you see Nancy Pelosi?” Another asks: “Where the fuck is Nancy?” Outside, a bearded man in a “Maga” cap picks up a phone and shouts: “Can I speak to Pelosi? Yeah, we’re coming, bitch.”

Pelosi is seen entering the military base at Fort McNair. As Congressman James Clyburn looks on, she says: “There has to be some way we can maintain the sense that people have that there is some security, some confidence that government can function and that we can elect the president of the United States.”

Chuck Schumer, then the Democratic minority leader in the Senate, informs Pelosi: “My wife just called watching TV. There are people with guns trying to get into the House chamber.”

Pelosi had to leave the Capitol without her phone so is forced to borrow others’. Sitting and studying a photo on one phone, says: “Oh, one of them is in the president of the Senate’s seat.”

Schumer notes that some senators are still in hiding and pleads by phone with Ryan McCarthy, the army secretary, to send in military personnel. Pelosi, watching the carnage on CNN, speaks to Ralph Northam, the governor of Virginia: “They’re just breaking windows. This is horrendous. And all at the instigation of the president of the United States.”

She tells Schumer that Northam agreed to dispatch 200 state police and a national guard unit.

At 3.30pm Pelosi and Schumer speak by phone to Jeffrey Rosen, the acting attorney general. Pelosi tells him: “Safety just transcends 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.”

Schumer adds sharply: “Why don’t you get the president to tell them to leave the Capitol, Mr Attorney General, in your law enforcement responsibility? A public statement they should all leave?”

Rosen begins to say his team is “coordinating as quickly and as –” before getting cut off by Schumer, who demands: “No, no, no – please answer my question, answer my question!”

Congressional leaders then have a call with the acting defence secretary, Christopher Miller. Pelosi says forcefully: “Just pretend for a moment it was the Pentagon or the White House or some other entity that was under siege. You can logistically get people there as you make the plan and you have some leadership of the national guard there they have not been given the authority to activate.”

Then Pelosi speaks to Pence as he waits in a parking garage beneath the Capitol, where rioters chanted for him to be hanged.

Taking a seat beside a plant and cabinet full of decorative plates, the speaker says she and other congressional leaders are OK, then asks: “How are you? Oh, my goodness, where are you? God bless you. But are you in a very safe –?”

She says she has been told that it will “take days” to clear the Capitol and that Fort McNair has facilities for the House and Senate to meet, adding: “We’d rather go to the Capitol and do it there but it doesn’t seem to be safe.”

Pelosi continues: “We’ve got a very bad report about the condition of the House floor, with defecation and all that kind of thing.”

She is then seen using her teeth to help unwrap a beef jerky stick and eating while holding the phone in her right hand. She tells Pence: “I worry about you being in that Capitol room. Don’t let anybody know where you are.”

Finally, Trump releases a video calling his supporters to go home, but Pelosi and Schumer are not impressed. She comments: “Insurrection. That’s a crime and he’s guilty of it.”

By 5.45pm the security forces have regained control. Pence informs Pelosi and Schumer by phone that Congress will be able to reconvene. The backup plan of doing so at Fort McNair is therefore not necessary.

Sitting in a vehicle heading back through darkened streets, Pelosi expresses her disgust towards Trump. “I just feel sick at what he did to the Capitol and to the country today. He’s got to pay a price for that.”

Back inside the Capitol, Pelosi is informed that the sign outside her office has been taken. She responds phlegmatically: “They took the sign? We’ll get another.”

Entering the office, she is warned that there is still a lot of broken glass. A gold framed mirror above the fireplace is smashed. She observes: “Boy, the staff looks scared. They’re traumatised.”

The Senate reconvenes around 8pm and the House around 9pm. Pelosi watches on TV as Schumer compares the insurrection to the attack on Pearl Harbor as a “day of infamy”. At 3.48am on 7 January, Joe Biden’s election victory is ratified after all.

At 9am Pelosi is in a car, telling Clyburn: “We have to stop this man, the insurrectionist in the White House.” Clyburn warns that invoking the 25th amendment would be a “complicated process” and there may not be enough time, “but there is enough time – and it’s rather simple – to tag him with the uniqueness of a second impeachment”.

On 13 January, a week before he left office, the House voted to impeach Trump by a vote of 232-197 for incitement of insurrection. He was the first president in history to be impeached twice.