WASHINGTON (Reuters) - A woman who has accused President Donald Trump’s Supreme Court nominee, Brett Kavanaugh, of sexual assault decades ago wants her allegations to be investigated by the FBI before she appears at a U.S. Senate hearing, her lawyers said on Tuesday.

The development further roiled a confirmation process that once seemed smooth for Kavanaugh, whose confirmation to the lifetime post could consolidate the conservative grip on the top U.S. court.

Christine Blasey Ford, a university professor in California, has accused Kavanaugh of attacking her and trying to remove her clothing while he was drunk at a suburban Maryland party in 1982 when they were both high school students, allegations Kavanaugh has called “completely false.”

The Senate Judiciary Committee, which is overseeing the nomination, had called a hearing for Monday to examine the matter, and the White House had said Kavanaugh was ready to testify.

In a letter to the committee’s chairman, Republican Senator Chuck Grassley, Ford’s attorneys said an FBI investigation needed to come first.

"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 lawyers wrote. A copy of the letter was posted on the committee's website. (bit.ly/2OAJWD0)

Grassley said there is no reason to delay Ford’s testimony and an invitation for her to appear before the committee on Monday stands.

“Dr Ford’s testimony would reflect her personal knowledge and memory of events. 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,” Grassley said in a statement.

Democrats, already fiercely opposed to the nominee, have also been seeking an FBI investigation, a request that Republicans have rebuffed. Trump and other Republicans said they did not think the FBI needed to be involved.

A hearing would represent a potential make-or-break moment for the conservative federal appeals court judge’s confirmation chances, as Trump pursues his goal of moving the federal judiciary to the right.

“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,” Trump tweeted late on Tuesday.

Republicans control the Senate by only a narrow margin, meaning any defections within the party could sink the nomination and deal a major setback to Trump.

Earlier on Tuesday, Senator Lindsey Graham, one of the committee’s Republicans, said the panel would vote on the nomination next week whether or not Ford testified. A vote in committee would be a precursor to action in the full Senate.

FILE PHOTO: Supreme Court nominee Brett Kavanaugh testifies during the third day of his confirmation hearing before the Senate Judiciary Committee on Capitol Hill in Washington, U.S., September 6, 2018. REUTERS/Alex Wroblewski/File Photo

“If she does not want to come Monday, publicly or privately, we’re going to move on and vote Wednesday,” he told Fox News Channel.

TRUMP STANDS BY NOMINEE

In a statement on Monday, a representative for the Justice Department said the FBI had followed protocol forwarding information about the allegation to the White House.

“The FBI’s role in such matters is to provide information for the use of the decision makers,” the statement said.

Trump earlier on Tuesday stepped up his defense of Kavanaugh and expressed sympathy toward his nominee, who met with officials at the White House for a second straight day, although not with the president.

“I feel so badly for him that he’s going through this, to be honest with you,” Trump told a news conference. “This is not a man that deserves this.”

“Hopefully the woman will come forward, state her case. He will state his case before representatives of the United States Senate. And then they will vote,” Trump added.

Senator John Cornyn, a member of the Senate Republican leadership, appeared to cast doubt on Ford’s allegations.

“We just don’t know what happened 36 years ago and there are gaps in her memory. She doesn’t know how she got there, when it was, and so that would logically be something where she would get questions,” Cornyn told reporters.

Cornyn’s fellow Republicans have generally avoided criticizing Ford, instead castigating Democrats for not revealing her allegations earlier.

The confirmation fight comes just weeks before the Nov. 6 congressional elections in which Democrats are seeking to take control of Congress from Trump’s fellow Republicans, which would be a major blow to the president’s agenda.

‘HATE MAIL, HARASSMENT, DEATH THREATS’

Ford detailed her allegation in a letter sent in July to Senator Dianne Feinstein, the committee’s top Democrat. The letter’s contents leaked last week and Ford identified herself in an interview with the Washington Post published on Sunday that included details about the alleged assault.

In a statement, Feinstein, said the committee should accede to Ford’s wishes and postpone Monday’s hearing.

“A proper investigation must be completed, witnesses interviewed, evidence reviewed and all sides spoken to. Only then should the chairman set a hearing date,” she said in a statement.

Lisa Banks, an attorney for Ford, told CNN her client was dealing with “hate mail, harassment, death threats” and that her immediate focus was protecting herself and her family.

Democrats have objected to the proposed hearing format, with Feinstein arguing there should be more than just two witnesses, possibly to include people in whom Ford previously confided. The committee’s Democrats said witnesses should include Kavanaugh’s friend Mark Judge, who Ford has said witnessed the alleged incident.

A lawyer representing Judge sent a letter to Grassley saying Judge did not want to speak publicly about the matter.

“In fact, I have no memory of this alleged incident. Brett Kavanaugh and I were friends in high school but I do not recall the party described in Dr Ford’s letter. More to the point, I never saw Brett act in the manner Dr Ford describes,” the letter quoted Judge as saying.

Judge is the author of a 1997 memoir titled “Wasted: Tales of a Gen X Drunk,” which recounts his experiences as a teenage alcoholic.

One Democratic senator, Richard Blumenthal, said Kavanaugh should withdraw his nomination.

“I believe Dr Ford. I believe the survivor here,” Blumenthal said. “She has come forward courageously and bravely, knowing she would face a nightmare of possible and vicious scrutiny.”

The showdown has echoes of current Supreme Court Justice Clarence Thomas’ contentious confirmation hearings in 1991 involving sexual harassment allegations lodged against him by a law professor named Anita Hill.

Thomas, the court’s second black justice, was ultimately confirmed, but only after a nasty televised hearing in which Hill faced pointed questions from Republican senators and the nominee said he was the victim of “a high-tech lynching for uppity blacks.”