In a bombshell development in the already contentious confirmation process of U.S. Supreme Court nominee Brett Kavanaugh, longtime government employee Julie Swetnick, in a sworn declaration signed under penalty of perjury, alleges that during house parties in the early 1980s, Kavanaugh and other high school friends of his caused "girls to become inebriated and disoriented so they could be 'gang raped,'" and that Swetnick was the victim of one of these assaults.

Swetnick's attorney Michael Avenatti revealed his client's identity and shared the highly anticipated details of her allegations in a tweet on Wednesday, along with screenshots of his emails to Mike Davis, the top Republican nominations staffer for the Senate Judiciary Committee, which Avenatti says were ignored:

Below is my correspondence to Mr. Davis of moments ago, together with a sworn declaration from my client. We demand an immediate FBI investigation into the allegations. Under no circumstances should Brett Kavanaugh be confirmed absent a full and complete investigation. pic.twitter.com/QHbHBbbfbE — Michael Avenatti (@MichaelAvenatti) September 26, 2018

This is just the latest in a series of sexual assault allegations women have levied at Kavanaugh throughout his confirmation process. Professor Christine Blasey Ford, who is scheduled to testify for the Senate committee on Thursday, says that during a high school party, he attempted to rape her while his friend Mark Judge watched. Deborah Ramirez told The New Yorker that at a dorm party while they were both students at Yale, the nominee "thrust his penis in her face, and caused her to touch it without her consent."

Swetnick has held numerous security clearances as an employee of multiple federal agencies, including the State, Justice, Treasury, and Homeland Security departments. In the declaration Avenatti shared on Twitter, Swetnick says she attended "well over ten house parties in the Washington, D.C. area during the years 1981-1983 where Mark Judge and Brett Kavanaugh were present."

At these parties, she says, she witnessed Kavanaugh "drink excessively," behave as a "mean drunk," and "engage in abusive and physically aggressive behavior toward girls, including pressing girls up against him without their consent, 'grinding' against girls, and attempting to remove or shift girls' clothing to expose private body parts."

The declaration says that in the early 1980s, she became aware of efforts by Judge, Kavanaugh, and others to "spike" the "punch" at such parties, "so as to cause girls to lose their inhibitions and their ability to say 'no.'" The girls were then allegedly taken to "a side room or bedroom" to be gang raped.

"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," Swetnick recalls. "These boys included Mark Judge and Brett Kavanaugh."

Around 1982, Swetnick says she believes someone drugged her drink, and later that night she became the victim of one of these assaults. Both Judge and Kavanaugh "were present" during the attack, she says. "I was incapacitated without my consent and unable to fight off the boys raping me."

She adds that she told multiple people after she was assaulted, and that there are witnesses "who can attest to the truthfulness of each of these statements." In Avenatti's emails to Davis and his tweet on Wednesday, he demands "an immediate FBI investigation" into his client's claims.

"She is prepared to meet with the FBI, disclose everything that she knows, disclose additional witnesses," and "absolutely" willing to testify before the Senate Judiciary Committee, Avenatti added, appearing by phone on MSNBC following his tweet on Wednesday. "The allegations in this declaration are shocking. They are also detailed, and my client stands behind them 100 percent."

"My client has been issued a number of security clearances by the federal government over the years. She has been fully vetted, time and time again, and she is an honest and courageous woman," he said, calling on the Senate to refrain from rushing a vote on Kavanaugh's confirmation. "We want there to be a deliberative process by which all of these allegations are investigated thoroughly and then ultimately, once all of the facts are obtained, then and only then should Brett Kavanaugh's nomination be considered."

"And frankly, I think in light of these allegations, as well as Dr. Ford's, as well as Ms. Ramirez's, as well as others," he concluded, "there can be no question that the nomination of Brett Kavanaugh should be immediately withdrawn."

In a statement circulated by the White House, Kavanaugh responded to Swetnick's allegations, saying: "This is ridiculous and from the Twilight Zone. I don't know who this is and this never happened."

This post has been updated with additional comment from Michael Avenatti and Brett Kavanaugh.