In a letter to Senate Judiciary Committee chairman Chuck Grassley (R-Iowa) on Saturday, Sen. Bernie Sanders (I-Vt.) demanded that the newly reopened FBI investigation into Supreme Court nominee Brett Kavanaugh examine both the serious accusations of sexual assault against him and whether he lied to Congress in his testimony.

"If a thorough investigation takes longer than a week, so be it. First and foremost, we need the truth."

—Sen. Bernie Sanders

"In order for this FBI investigation regarding Judge Brett Kavanaugh’s nomination to be complete," Sanders wrote, "it is imperative the bureau must not only look into the accusations made by Dr. Ford, Deborah Ramirez, and Julie Swetnick, it should also examine the veracity of his testimony before the Judiciary Committee."

The Vermont senator went on to call on the Senate to not "constrain" the FBI probe to one week, arguing that a truly thorough probe could take longer.

"If you are concerned with a delay in this confirmation process, remember that Senate Republicans refused to allow the Senate to consider Merrick Garland’s nomination to the Supreme Court for nearly a year," Sanders wrote. "In addition to investigating the accusations made by multiple women, a thorough investigation should include a review of Judge Kavanaugh’s numerous untruthful statements in his previous testimony before Congress."

Lying to Congress is a federal crime. The FBI must examine the veracity of Kavanaugh’s statements under oath in addition to the sexual assault allegations against him. Kavanaugh's truthfulness with the Senate goes to the very heart of whether he should be confirmed to the court. pic.twitter.com/TsNOTm4fxK — Bernie Sanders (@SenSanders) September 29, 2018

Even prior to the emergence of credible sexual assault allegations against him, Kavanaugh—who on Thursday repeatedly refused to endorse an FBI probe into the allegations against him—was accused by several Democratic senators of lying to the Senate during hearings for his nomination to the U.S. Court of Appeals in 2004 and 2006.

In his letter to Grassley on Saturday, Sanders listed some of these examples, as well as statements Kavanaugh made "under oath regarding his treatment of women and his use of alcohol," which "appear not to be true."

Read Sanders' full letter: