WASHINGTON — Christine Blasey Ford told Congress on Thursday that she believes Supreme Court nominee Brett Kavanaugh attempted to rape her when they were at a gathering of teenagers at a Maryland home in 1982.

In her opening remarks, she detailed the alleged assault, as well as offer to the committee her motivation for coming forward. She said she had one beer that evening while Kavanaugh and his friend, Mark Judge, who she alleges witnessed the attack, were "visibly drunk."

"Brett groped me and tried to take off my clothes. He had a hard time because he was so drunk, and because I was wearing a one-piece bathing suit under my clothes," Ford said, after describing how she was pushed into a bedroom on the second floor of the home. "I believed he was going to rape me."

She added how she tried to yell for help.

"When I did, Brett put his hand over my mouth to stop me from screaming. This was what terrified me the most, and has had the most lasting impact on my life," she said. "It was hard for me to breathe, and I thought that Brett was accidentally going to kill me. Both Brett and Mark were drunkenly laughing during the attack. "

In addition, Ford said that she told "very few friends" over the years about this “traumatic experience” — but that all changed in July when she learned that Kavanaugh was on President Donald Trump’s short list to serve on the Supreme Court.

“My motivation in coming forward was to provide the facts about how Mr. Kavanaugh’s actions have damaged my life, so that you can take that into serious consideration as you make your decision about how to proceed,” Ford said. “It is not my responsibility to determine whether Mr. Kavanaugh deserves to sit on the Supreme Court. My responsibility is to tell the truth.”

Kavanaugh, in his prepared testimony, will again reject Ford's allegation.

"I categorically and unequivocally deny the allegation against me by Dr. Ford," he's expected to say, according to prepared testimony released by the Senate Judiciary Committee Wednesday. "I never had any sexual or physical encounter of any kind with Dr. Ford. I am not questioning that Dr. Ford may have been sexually assaulted by some person in some place at some time. But I have never done that to her or to anyone. I am innocent of this charge."

He's also expected to say that during high school, most of his focus was on "academics, sports, church, and service."

"But I was not perfect in those days, just as I am not perfect today," he is expected to add. "I drank beer with my friends, usually on weekends. Sometimes I had too many. In retrospect, I said and did things in high school that make me cringe now. But that’s not why we are here today. What I’ve been accused of is far more serious than juvenile misbehavior. I never did anything remotely resembling what Dr. Ford describes."

Judge, the high school friend of Kavanaugh's who Ford alleges witnessed the attack, told the Senate in a letter last week that he had no memory of the alleged incident.

In a timeline of allegations against Kavanaugh released by Grassley Wednesday night, Grassley's office wrote that two men came forward to the committee, one on Monday and one Wednesday, to say they believe they "had the encounter" with Ford in 1982, not Kavanaugh. The men were not named in the timeline.

"Twelve hours before the hearing they suggest two anonymous men claimed to have assaulted her," an unnamed Democratic committee aide responded in a statement. "Democrats were never informed of these assertions or interviews, in violation of Senate rules."

Ford and Kavanaugh's prepared testimony comes after attorneys for Ford gave the Senate Judiciary Committee sworn declarations from four individuals, including her husband, who say she told them in recent years that Kavanaugh attacked her when they were in high school.

The signed documents — from Ford's husband, Russell, and three friends — were sent to the committee on Tuesday night and obtained by NBC News Wednesday morning, the day before Ford and Kavanaugh are scheduled to testify before the committee about the allegations. The story was first reported by USA Today.

Read the sworn declarations sent to the Senate Judiciary Committee

In one declaration, a friend of Ford, Keith Koegler, says that Ford told him of the alleged assault in early summer 2016, while they were talking about the sentencing of ex-Stanford swimmer Brock Turner, who was convicted of sexually assaulting an unconscious woman.

"Christine expressed anger at Mr. Turner's lenient sentence, stating that she was particularly bothered by it because she was assaulted in high school by a man who was now a federal judge in Washington, D.C.," Koegler said.

Koegler said Ford didn't mention the assault again until "June 29, 2018, two days after Justice Anthony Kennedy announced his resignation from the Supreme Court of the United States."

Koegler added that, after he asked in an email for the name of the person who allegedly assaulted her, she replied, "Brett Kavanaugh."

In another declaration, Adela Gildo-Mazzon, a friend of Ford's, said Ford confided in her about the alleged assault in 2013.

"Christine told me she had been having a hard day because she was thinking about an assault she experienced when she was much younger. She said she had been almost raped by someone who was now a federal judge. She told me she had been trapped in a room with two drunk guys, and that she had escaped, ran away and hid," Gildo-Mazzon wrote.

Russell Ford said in his declaration that his wife first told him of the alleged sexual assault around the time they got married, in June 2002, but that she didn't share all of the details until a couple's therapy session in 2012.

"She said that in high school she had been trapped in a room and physically restrained by one boy who was molesting her while another boy watched. She said she was eventually able to escape before she was raped," Russell Ford said in the statement.

"I remember her saying that the attacker's name was Brett Kavanaugh, that he was a successful lawyer who had grown up in Christine's hometown, and that he was well-known in the Washington D.C. community," Russell Ford added.

In the fourth declaration, Rebecca White, a neighbor and friend of Ford's, said Ford told her in 2017 that when "she was a young teen, she had been sexually assaulted by an older teen."

"I remember her saying that her assailant was now a federal judge," White said.

All four made their sworn declarations "under the penalties of perjury," according to the documents. Kavanaugh has vigorously denied all allegations against him.

Separately, Sens. Dick Durbin, D-Ill., and Tammy Duckworth, D-Ill., accepted an open letter Wednesday in support of Ford that was signed by 1,400 men and women "who grew up in the same world" as Ford and Kavanaugh in the suburbs of Maryland near Washington, D.C.

"We attended the same elite private schools, country clubs, and churches. And we believe you," said the letter.

"Each one of us heard your story and not one of us was surprised," it added. "These are the stories of our lives and our friends' lives. We know the terrible impact of sexual assault, coercive behavior, and harassment that pervaded the culture of our youth and continues today. And we understand why girls and women often do not report their attackers because of the fear of being disbelieved, shamed, and ostracized."

Read the results of a polygraph test taken by Ford

Trump, defending his nomination of Kavanaugh, told reporters on Wednesday that Senate Republicans "could've pushed it through two and a half weeks ago, and you wouldn’t be talking about it right now, which is frankly what I would've preferred, but they didn't do that."

A spokesman for Senate Judiciary Committee Chairman Chuck Grassley, R-Iowa, said Wednesday morning that while attorneys for Ford have provided them with the sworn declarations supporting Ford's allegations, the therapist's notes and the polygraph results cited in the original report by The Washington Post had not yet been turned over.

"They were conspicuously absent although they were both requested," George Hartmann told NBC News.

Later Wednesday, Ford's attorneys responded to Grassley's request for documents, releasing the polygraph results to the Senate Judiciary Committee. But in the accompanying letter, the lawyers, Debra Katz and Lisa Banks, said they would not produce copies of Ford's "medical records."

"These records contain private, highly sensitive information that is not necessary for the Committee to assess the credibility of her testimony," Ford's attorneys wrote.

Grassley, in letter dated Sept. 23, had requested the results of the polygraph and "copies of any and all written, audio-visual, or electronic materials relating to the allegations raised by Dr. Ford against Judge Kavanaugh that Dr. Ford or her representative previously provided to any member of the United States Senate, any Member of the House of Representatives, or any reporter or other agent of a press outlet."

The Post, for their story that revealed Ford as Kavanaugh's accuser, said it reviewed portions of a therapist's notes from 2012 that were provided by Ford. Kavanaugh is not named, but according to The Post, the notes record that Ford said "she was attacked by students 'from an elitist boys' school' who went on to become 'highly respected and high-ranking members of society in Washington.'"

"Any request that she expose her private medical records for public inspection represents an unacceptable invasion of privacy to which no person would consent. Under no circumstances will we grant any such request," Ford's lawyers said Wednesday.

Kavanaugh also faces allegations from a second woman, Deborah Ramirez, who alleges he exposed himself to her while both were in college.

Her attorneys sent a letter to Grassley and ranking member Sen. Dianne Feinstein, D-Calif., on Wednesday reiterating Ramirez's willingness to come before members of the Judiciary Committee and noting that "the majority staff thus far has refused to even speak with Ms. Ramirez's counsel."