WASHINGTON－President Donald Trump's embattled Supreme Court nominee Brett Kavanaugh was hit by a second accusation of sexual misconduct on Sunday, leaving Republicans scrambling to save a confirmation that until recently had seemed all but certain.

The latest claims of impropriety during Kavanaugh's youth came as he was already facing a dramatic hearing where his testimony was to be weighed against that of a university professor who has separately accused him of assault.

Senate Democrats are now investigating a bombshell claim by Deborah Ramirez, 53, who says Kavanaugh exposed himself to her during a 1980s college party at Yale University, thrust his genitals in her face and caused her to touch them without her consent, according to The New Yorker.

Ramirez told the magazine she had become inebriated during a drinking game and was on the floor when the alleged incident took place.

Kavanaugh denied the story, calling it "a smear".

"The people who knew me then know that this did not happen, and have said so," the judge said in a statement.

Like Christine Blasey Ford, the professor accusing him of assaulting her when they were teenagers, Ramirez wants the FBI to investigate the incident, and Democratic lawmakers are backing their demands.

Ramirez's call for an investigation came despite her admission to the New Yorker that there are gaps in her memory of the incident, and that she expects her memories to be questioned as she had been drinking.

Ford, meanwhile, agreed to testify on Thursday after an increasingly ugly weeklong standoff that saw her forced to leave her California home as she faced death threats and Trump attacked her credibility.

Kavanaugh, who also denies that allegation, said he wishes to testify as soon as possible to clear his name following Ford's claims that he attacked her at a high school party.

According to The New York Times, the federal judge has calendars from the summer of 1982 he plans to share with senators showing he was out of town most of that time with no indication of the party of concern.

Democratic Senator and committee member Richard Blumenthal echoed demands for an investigation.

"The Senate simply cannot in good conscience vote on this nomination without a full fair FBI investigation of all these allegations," he said.

AFP