The vote on confirming Kavanaugh as an associate justice will begin at roughly 3:30 p.m., and senators have been advised to be in their seats by the time the historic roll call begins.
The chamber voted 51-49 to move forward with President Donald Trump's nominee.
Kavanaugh staunchly denied the allegations, but almost all Senate Democrats voted against his confirmation.
Sen. Lisa Murkowski, R-Alaska, was the sole undecided senator to vote no. Hundreds have been arrested on Capitol Hill this week.
Some raised their fists as they were escorted down the steps.
Kavanaugh seems assured of surviving a Supreme Court nomination fight for the ages after two wavering senators said they'd back him despite weeks of shocking accusations, hardball politics and rowdy Capitol protests.
His promotion to the Supreme Court will also stand as a demoralizing defeat for Democrats who battled hard to block the 53-year-old judge at all costs. Kavanaugh has denied the allegations against him.
"Millions of Americans, millions of women are watching us today", said New York Sen. Democrats argue that Trump picked Kavanaugh, in part, because he is likely to vote to overturn that ruling.
"What I can speak to is when victims of sexual assault and violence go to their Congress people - when they go to their senators and they ask for their information to be confidential, I think that that's a request that needs to be respected", Katz said.
In the end, three of those four undecideds - Collins, Flake and Manchin - voted to end debate.
If true, those texts would contradict sworn testimony Kavanaugh gave to senators when he said the first time he heard of the allegations was when they appeared in print.
Senate Republicans, not the White House, set the scope of the Federal Bureau of Investigation probe into sexual assault allegations against Brett Kavanaugh, including the decision not to interview the Supreme Court nominee or accuser Christine Blasey Ford, said Senate Majority Leader Mitch McConnell. They said he also seemed ready to knock down President Barack Obama's health care law and to rule for Trump if federal authorities probing his 2016 campaign's alleged connections to Russian Federation try to pursue him in court.
And in a statement issued soon after Collins spoke, Manchin explained he was supporting Kavanaugh notwithstanding the "serious accusations" leveled against the judge and lingering questions about Kavanaugh's temperament. Manchin is up for re-election this November in West Virginia. She has faced pressure from home state Alaskans, including Native Alaskan women, who have described the scourge of sexual assault. In addition, Republican Senator Jeff Flake has also indicated he is a yes vote.
After Collins' announcement that she is pledging her support, Sen.
Democrats said the allegations were credible and deserved a full investigation, while Republicans accused Democrats of using uncorroborated allegations to scuttle or delay the nomination - leading to a stream of angry flashpoints between lawmakers. "And that is hard". "I admire her a lot", he said. Steve Daines of Montana, who supports Kavanaugh but was in Montana to walk his daughter down the aisle at her wedding.
"If both are believable, we must still find a way to analyze the evidence to help us reach a conclusion", Kyl said. "It will not change the outcome of the vote".
Which, maybe! As I said above, nothing is official until the final confirmation vote happens on Saturday. So did Collins and Manchin - and that fact was not lost on Kavanaugh's opponents, who also packed Manchin's office to persuade him to side with his fellow Democrats.
Mr Trump praised the Senate, tweeting: "Very proud of the U.S. Senate for voting "YES" to advance the nomination of Judge Brett Kavanaugh!".