The future of Donald Trump’s nominee for the Supreme Court has been thrown into fresh doubt after a third woman came forward to accuse Brett Kavanaugh of sexual offences or misconduct, claiming the judge was present during a gang rape and frequently drugged young women to enable them to be assaulted.

Just 24 hours before the Senate Judiciary Committee was to hear from Mr Kavanaugh and Christine Blasey Ford, who has accused him of sexually assaulting her at a high school party three decades ago, attorney Michael Avenatti added a dramatic 11th hour twist – identifying Julie Swetnick as a woman who claimed to have been present at parties when Mr Kavanaugh and one of his close friends, Mark Judge, carried out a number of alleged crimes, including drugging young women so that they could be raped by a succession of boys.

Mr Kavanaugh has dismissed the latest claims as has all the claims of sexual assault as an attempt to derail his confirmation. “This is ridiculous and from the twilight zone. I don’t know who this is and this never happened,” he said. Mr Judge has also denied the allegations.

On Wednesday, Senate Democratic leader Chuck Schumer called on Mr Kavanaugh to withdraw in light of the latest sexual misconduct allegations against him, and said if he did not, an FBI investigation was needed before any senate vote.

“If our Republican colleagues proceed without an investigation, it would be a travesty for the honour of the Supreme Court and our country,” Mr Schumer said.

For now, Mr Trump is sticking with his man. “Avenatti is a third rate lawyer who is good at making false accusations, like he did on me and like he is now doing on Judge Brett Kavanaugh. He is just looking for attention and doesn’t want people to look at his past record and relationships – a total low-life,” he tweeted.

Republicans on the Senate Judiciary Committee said they wanted to speak to Ms Swetnick. Senator John Kennedy of Louisiana said the committee would be be extending an invitation to Ms Swetnick to provide a sworn statement, and South Carolina’s Lindsey Graham said he wanted the committee to talk to her “today”.

They spoke after news spread of the allegations made by Ms Swetnick in an an explosive signed document that has been sent to the Senate Judiciary Committee. Ms Swetnick said in the 1980s, she witnessed efforts by Mr Kavanaugh and Mr Judge to get teenage girls “inebriated and disoriented so they could then be “gang raped” in a side room or bedroom by “a train of numerous boys”.

“I have a firm recollection of seeing boys lined up outside rooms at many of these parties waiting for their ‘turn’ with a girl inside the room,” she said in the statement. “These boys included Mark Judge and Brett Kavanaugh.”

Mr Kavanaugh, 53, has repeatedly denied the sexual assault and misconduct allegations levelled against him – now from three women.

Ms Swetnick said she has not alleged Mr Kavanaugh had sexually assaulted her.

Two other women, Christine Blasey Ford and Deborah Ramirez, have come forward with their own allegations against Mr Kavanaugh. Mr Ford has claimed the judge held her down and tried to remove her clothes while they were both in high school in Maryland.

Ms Ramirez alleged that Kavanaugh exposed himself to her while they were freshmen at Yale University. Ms Ford has provided senators with sworn testimony from people who say she had spoken about the alleged assault several years ago.

In her declaration, Ms Swetnick alleges that in 1982, she “became the victim” of one of these rapes “where Mark Judge and Brett Kavanaugh were present”.

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She says she told at least two people what had happened and she says she was incapacitated and “unable to fight off the boys raping me” Ms Swetnick believes she was drugged with Quaaludes “or something similar placed in what I was drinking”.

Ms Swetnick has said there were at least 10 house parties in the Washington, DC area she attended, and that Mr Kavanaugh and Mr Judge was always there.

“I observed Brett Kavanaugh drink excessively at many of these parties and engage in abusive and physically aggressive behaviour towards girls, including pressing girls against him without their consent, “grinding” against girls and attempting to remove or shift girls’ clothing to expose private body parts,” she wrote.

She adds: “I likewise observed him be verbally abusive towards girls by making crude sexual comments to them that were designed to demean, humiliate and embarrass them. I often witnessed Brett Kavanaugh speak in a demeaning manner about girls in general as well as specific girls by name. I also witnessed Brett Kavanaugh behave as a “mean drunk” on many occasions at these parties.”

An lawyer for Mr Judge, denied the claims, according to MSNBC. “Mr Judge vehemently denies Ms. Swetnick’s allegations.”

Mr Swetnick, who attended high school in Gaithersburg, Maryland, claims that she attended the parties with Mr Kavanaugh and Mr Judge between 1981 and 1983. In her sworn statement, she said she held “active clearances” for her work with the US Department of Treasury, US Mint and Internal Revenue Service. She said she also previously had security clearances with the US Department of State, Department of Justice, Department of Homeland Security and Customs and Border Protection.