WASHINGTON, United States (AFP) — A defiant Brett Kavanaugh, President Donald Trump’s nominee for the US Supreme Court, angrily denied sexual assault allegations on Thursday and condemned his bitter Senate confirmation process as a “national disgrace.”

Kavanaugh’s passionate defence came after a university professor, Christine Blasey Ford, told the Senate Judiciary Committee that he sexually assaulted her 36 years ago.

The allegations against the 53-year-old conservative judge have thrust the Trump administration into the #MeToo movement’s harsh glare, and threaten to derail its bid to tilt the nation’s highest court to the right for years to come.

“I categorically and unequivocally deny the allegation by Dr Ford,” said Kavanaugh, whose voice shook with anger during an opening statement that saw him repeatedly shed tears. “I’ve never sexually assaulted anyone, not in high school, not in college, not ever.”

“I am innocent of this charge,” Kavanaugh thundered.

Earlier, during four hours of emotionally-charged testimony, Blasey Ford, 51, said she was “100 per cent” certain Kavanaugh was her assailant and it was “absolutely not” a case of mistaken identity.

“I am here today not because I want to be,” Blasey Ford said as she recounted the sexual assault which she alleged occurred at a high school party at a suburban Maryland home in 1982.

“I am terrified,” she said, her voice often quavering. “I am here because I believe it is my civic duty to tell you what happened to me.”

Kavanaugh slammed what he called a “grotesque and coordinated character assassination” and a “calculated and orchestrated political hit.”

“My family and my name have been permanently destroyed by vicious and false accusations,” Kavanaugh said.

“This confirmation process has become a national disgrace.”

But he said he would not withdraw his candidacy for a spot on the nine-member Supreme Court.

“I will not be intimidated into withdrawing from this process,” Kavanaugh said. “You may defeat me in the final vote but you’ll never get me to quit. Never.”

Democrats on the committee praised Blasey Ford’s courage in coming forward while a senior Republican senator accused the opposition party of seeking to delay the nomination until after midterm elections in November.

Blasey Ford, wearing glasses and a sober dark blue suit, appeared nervous but poised as she sat at the witness table, consulting occasionally with her lawyer.

A psychology professor who is married with two children, she said Kavanaugh and a friend of his, Mark Judge, were drunk at the 1982 party when they pushed her into a bedroom.

“Brett and Mark came into the bedroom and locked the door behind them,” she said. “I was pushed onto the bed and Brett got on top of me.

“He began running his hands over my body and grinding into me,” she said. “I believed he was going to rape me.

“I tried to yell for help,” she said. “When I did, Brett put his hand over my mouth to stop me from yelling.

“It was hard for me to breathe, and I thought that Brett was accidentally going to kill me,” she said.

She said her most powerful memory was “the uproarious laughter between the two, and them having fun at my expense.”

Blasey Ford said she managed to escape when Judge jumped on the bed, sending them all toppling. Trump nominated Kavanaugh to replace Justice Anthony Kennedy, who had been a swing vote on a court now divided between four conservative and four liberal justices.

The Republican president has fiercely defended his pick — but said he would watch the highly charged hearing and was open to changing his mind.

The White House confirmed that Trump watched the testimony aboard Air Force One as he returned to Washington from New York.

Senator Richard Blumenthal, a Democrat from Connecticut, told Blasey Ford he found her testimony “powerful and credible.”

“I believe you,” he said.

Blumenthal also hit out at Trump for failing to authorise an FBI investigation into Blasey Ford’s allegations.

“It’s up to the president of the United States and his failure to ask for an FBI investigation amounts to a cover-up,” he said.

A Republican senator, John Cornyn of Texas, said he “found no reason to find (Blasey Ford) not credible.”

But Senator Lindsey Graham, a Republican from South Carolina, hit out at the Democrats following Blasey Ford’s testimony.

“I did not find her allegations to be corroborated against Mr Kavanaugh,” Graham said. “I don’t doubt that something happened to her, but she can’t say the house, the city, the month of the year.

“Their goal is to delay this past the midterms,” he said. “They lay this past the midterms so that they can win the Senate and never allow Trump to fill the seat.”

Blasey Ford rejected any suggestions she had political motivations.

“Those who say that do not know me,” she said. “I am a fiercely independent person and I am no one’s pawn.”

Kavanaugh has also been accused of exposing himself to a classmate, Deborah Ramirez, during an alcohol-fuelled Yale University party a few years later.

On Wednesday, a third woman, Julie Swetnick, came forward with explosive allegations, saying she witnessed sexually abusive behaviour by Kavanaugh when he was a teenager.