Paul Pelosi, the husband of US House of Representatives Speaker Nancy Pelosi, is recovering from surgery after being attacked at home by a hammer-wielding intruder.

Mr Pelosi, 82, was left with a fractured skull and serious injuries to his right arm and hands.

The suspect is said to have demanded to see Mrs Pelosi after breaking into the San Francisco home.

A 42-year-old man has been arrested on charges including attempted homicide.

No motive is known.

Mrs Pelosi – who was on the other side of the country in Washington DC at the time of the assault – flew back to see her husband in hospital.

A spokesman for the senior Democrat said Mr Pelosi had been attacked in the early hours of Friday morning “by an assailant who acted with force, and threatened his life while demanding to see the Speaker”.

He was admitted to Zuckerberg San Francisco General Hospital for an operation and doctors expect a full recovery, said Mrs Pelosi’s spokesman, Drew Hammill.

In a news conference, San Francisco Police Chief William Scott said officers had responded to a call at around 02:27 local time (09:27 GMT) on Friday.

They found Mr Pelosi and the suspect – named by police as David DePape – struggling over a hammer, but it was wrested from Mr Pelosi by the intruder, who violently assaulted him with it. Mr Pelosi was bludgeoned at least once, said police.

The suspect was tackled and disarmed by officers. He had attempted to tie up Mr Pelosi “until Nancy got home”, law enforcement sources told CBS News. He reportedly shouted “where’s Nancy?” during the incident.

He is also facing charges of assault with a deadly weapon, burglary and several other felonies, Chief Scott said.

He said the suspect had gained access through a rear entryway to the four-bedroom Pelosi home in the upmarket neighbourhood of Pacific Heights. Footage shows a smashed glass door at the property.

Chief Scott told a Friday evening news conference that the alleged intruder was currently in hospital, though he declined to share details about his medical condition.

At the start of the break-in, Mr Pelosi told the intruder he needed to use the bathroom then made a secret 911 call on his mobile phone and left the line open, allowing a dispatcher to hear him talking to the suspect, reports the Los Angeles Times.

Chief Scott confirmed it was Mr Pelosi who had called police and that a quick-thinking emergency dispatcher had been “able to read between the lines” and send officers.

“This was not a random act,” said the police chief of the attack. “This was intentional.”

He added: “Everybody should be disgusted by what happened this morning.”

A blog, website and social media accounts under the name of the suspect seen by the BBC are filled with anti-Semitic memes, Holocaust denial, references to far-right websites and conspiracy theories such as QAnon.

He also posted debunked allegations of election fraud. His recent posts were rambling and touched on a host of far-right and extremist talking points.

Older messages by the suspect promote hemp jewellery and quartz crystals. He was also a nudist activist who had listed himself as a member of the Green Party, according to the San Francisco Chronicle.

The suspect grew up in the western Canadian province of British Columbia before moving to the US and becoming estranged from family members back home, his stepfather told the Globe and Mail newspaper.

Mrs Pelosi is one of the most powerful politicians in the country. She was re-elected to a fourth term as Speaker of the House of Representatives in 2021, making her second in line to the presidency after Vice-President Kamala Harris.

The Baltimore native has represented the San Francisco area in Congress since 1987, and typically splits her time between California and Washington DC.

She is currently fundraising and campaigning with Democrats around the country ahead of the midterm elections on 8 November.

Hours after the attack, the US government distributed a bulletin to law enforcement across the nation warning of a “heightened threat” of domestic violent extremism against candidates and election workers driven by individuals with “ideological grievances”.

Her husband, the multimillionaire founder of a venture capital firm, lives primarily in San Francisco, where he was born and raised.

The couple have been married since 1963 and have five children. Their combined net worth, primarily from Mr Pelosi’s investments, has made her one of the richest members of Congress.

Members of Congress have been on high-alert over security threats since the riot at the US Capitol in January 2021. Mrs Pelosi’s office in the building was ransacked by supporters of then-President Donald Trump during the attack.

In a statement, the White House said President Joe Biden was “praying for Paul Pelosi and for Speaker Pelosi’s whole family”.