Nancy Pelosi held back tears while talking about being awoken by pounding on the door as Capitol Police went to tell her about an attack on her husband at the family’s San Francisco home.

“I was very scared,” the US House of Representatives speaker told CNN in an interview.

“I’m thinking my children, my grandchildren. I never thought it would be Paul.”

On the eve of the US midterm elections, the Democratic leader opened up about the assault – as her party struggles against a surge of Republican enthusiasm to keep control of Congress at a time of rising threats of violence against politicians and concerns over the US election.

Mrs Pelosi’s husband, Paul, was smacked with a hammer by an intruder who authorities said broke into the family’s home – and was looking for the speaker – before hitting the 82-year-old in the head at least once.

The intruder allegedly told police he wanted to talk to Mrs Pelosi and would “break her kneecaps” as a lesson to other Democrats.

Mr Pelosi suffered a broken skull and other injuries in what authorities said was an intentional political attack.

Mrs Pelosi said she was sleeping at her apartment in Washington, having just returned from San Francisco, when there was a “bang, bang, bang, bang, bang” on her door. It was about 5am on the morning of October 28.

“We didn’t even know where he was or what his condition was,” Mrs Pelosi said, in excerpts of the interview scheduled to air later on Monday.

“We just knew there was an assault on him in our home.”

David DePape, 42, is being held without bail in San Francisco after entering a not guilty plea to attempted murder and other charges. He also faces federal charges of attempted kidnapping of an elected official.

The fringe activist, who followed conspiracy theories, broke into the Pelosi home, woke up Mr Pelosi and demanded to talk to “Nancy”, authorities said.

When Mr Pelosi told the intruder his wife was away, DePape allegedly said he would wait.

After Mr Pelosi called 911, officers arrived to see two men struggling over a hammer before DePape allegedly hit Mr Pelosi with the weapon.

DePape allegedly later told police he wanted to kidnap the speaker and threatened to hurt her “to show other members of Congress there were consequences to actions”.

The authorities’ stark narrative laid out in court filings in the case comes in contrast to the jokes and innuendo that conservatives and some Republican officials have spread about the Pelosis in the aftermath of the attack.

Mrs Pelosi has said little since the attack on her husband, cutting short her campaign appearances, but spoke in a virtual call to grassroots activists late last week after Mr Pelosi was released from the hospital.

“People say to me, ‘What can I do to make you feel better?’ I say: ‘Vote!’” Mrs Pelosi told those on the call.

Her voice cracked at times as she said of her husband’s recovery: “It’s going to be a long haul.”