Senate Democrats on Monday refused to participate in a phone call with Supreme Court nominee Brett Kavanaugh over an allegation that he attempted to sexually assault a girl at a party during high school, and instead insisted that the FBI is needed to investigate the claim.

The Judiciary Committee’s top Democrat, Sen. Dianne Feinstein of California, said Democrats “will not participate” in the phone call with Kavanaugh that’s scheduled with Senate Judiciary Committee staff at 5:30 p.m.