Christine Blasey Ford, who has accused Supreme Court nominee Brett Kavanaugh of sexual assault, is asking for an FBI investigation before she will agree to testify at a Senate hearing, according to a letter her attorneys sent Tuesday to the Senate Judiciary Committee.

Ford's two attorneys sent a letter to Judiciary Chairman Chuck Grassley, R-Iowa, saying that Ford has been targeted by "vicious harassment and even death threats" since coming forward with the allegations over the weekend.

"While Dr. Ford’s life was being turned upside down, you and your staff scheduled a public hearing for her to testify at the same table as Judge Kavanaugh in front of two dozen U.S. senators on national television to relive this traumatic and harrowing incident," attorneys Debra Katz and Lisa Banks wrote.

"The hearing was scheduled for six short days from today and would include interrogation by senators who appear to have made up their minds that she is 'mistaken' and 'mixed up.' While no sexual assault survivor should be subjected to such an ordeal, Dr. Ford wants to cooperate with the committee and with law enforcement officials."

Ford's attorneys said an FBI investigation "should be the first step in addressing her allegations."

"A full investigation by law enforcement officials will ensure that the crucial facts and witnesses in this matter are assessed in a non-partisan manner, and that the committee is fully informed before conducting any hearing or making any decisions," the letter says.

More: Who is Christine Blasey Ford

In a statement later Tuesday, Grassley said the committee's "invitation for Monday still stands."

"Dr. Ford’s testimony would reflect her personal knowledge and memory of events," Grassley said. "Nothing the FBI or any other investigator does would have any bearing on what Dr. Ford tells the committee, so there is no reason for any further delay."

In a late-night tweet, President Donald Trump said, "The Supreme Court is one of the main reasons I got elected President. I hope Republican Voters, and others, are watching, and studying, the Democrats Playbook."

Ford has alleged that Kavanaugh pinned her down on the bed of an upstairs room while they were both attending a party in Chevy Chase, Maryland, in 1982. She told The Washington Post that Mark Judge, a friend of Kavanaugh, watched and laughed as Kavanaugh tried to remove her clothes and held his hand over her mouth so she couldn't scream. All were teenagers at the time.

Judge has said he has no memory of the alleged assault and declined to testify.

Kavanaugh has denied the allegation, calling it "completely false." In a statement Monday, he said, “I have never done anything like what the accuser describes – to her or to anyone."

Earlier Tuesday, Trump defended Kavanaugh and said the FBI shouldn't investigate.

"We are looking to get this done as quickly as possible," Trump told reporters earlier in the day. "It’s a process. We all feel, speaking for all of the Republicans, we want to give everybody a chance to say what they have to say."

He added: “Judge Kavanaugh is anxious" to tell his side of the story.

As for a pre-hearing investigation, Trump said, "I don’t think the FBI should be involved because they don’t want to be involved."

More: Republicans insist onstrict timetable

Sen. Lindsey Graham, R-S.C., a member of the Judiciary Committee, said Wednesday that he believes an FBI investigation would do nothing more than delay Kavanaugh's confirmation.

"Requiring an FBI investigation of a 36-year-old allegation (without specific references to time or location) before Professor Ford will appear before the Judiciary Committee is not about finding the truth, but delaying the process until after the midterm elections," Graham said in a statement. "It is imperative the Judiciary committee move forward on the Kavanaugh nomination and a committee vote be taken as soon as possible."

Ford's call for an FBI investigation was echoed by Democratic members of the Senate Judiciary Committee.

Sen. Dianne Feinstein, D-Calif., released a statement Tuesday saying the scheduled Monday hearing is part of a "rushed" process.

“We should honor Dr. Blasey Ford’s wishes and delay this hearing," said Feinstein, the lead Democrat on the committee. "A proper investigation must be completed, witnesses interviewed, evidence reviewed and all sides spoken to. Only then should the chairman set a hearing date."

Sen. Mazie Hirono slammed the committee's move, forcefully saying, "Guess who's perpetuating all of these kind of actions? It's the men in this country. And I just want to say to the men in this country: Just shut up and step up."

Sen. Kamala Harris, D-Calif., said that Ford "should not be bullied" into taking part of a "biased" process.

Contributing: Erin Kelly, Richard Wolf, David Jackson, John Fritze