President Donald Trump’s Supreme Court nominee Brett Kavanaugh has gained the support of a key Republican senator.

The decision virtually ensures his nomination will advance to the full Senate a day after Mr Kavanaugh adamantly denied sexually assaulting Christine Blasey Ford, who insisted she was “100%” certain he did.

Moments before the panel convened, Arizona Senator Jeff Flake, a member of the committee, announced he would vote to confirm Mr Kavanaugh.

Mr Flake said Mr Kavanaugh was entitled to the “presumption of innocence … absent corroborating evidence”.

“While some may argue that a different standard should apply regarding the Senate’s advice and consent responsibilities, I believe that the Constitution’s provisions of fairness and due process apply here as well,” Mr Flake said.

“I will vote to confirm Judge Kavanaugh.”

The remarkable evidence before the panel saw Mr Kavanaugh angrily declared his innocence and Ms Ford calmly recount the moment in which she says he attacked her.

The American Bar Association, which previously gave Mr Kavanaugh its highest rating of “well qualified,” asked the Senate Judiciary Committee and the full Senate to delay the vote until the FBI could do a full background check on the assault claims.

White House spokeswoman Sarah Huckabee Sanders dismissed that on Friday, telling reporters Mr Kavanaugh has already “been through six separate background investigations by the FBI”.

Supreme Court Kavanaugh
Christine Blasey Ford gives evidence before the Senate Judiciary Committee (Win McNamee/AP)

The magazine of the Jesuit religious order in the United States withdrew its endorsement of Mr Kavanaugh, saying the nomination was no longer in the interests of the country and “should be withdrawn”.

“If Senate Republicans proceed with his nomination, they will be prioritising policy aims over a woman’s report of an assault,” the America magazine editors wrote.

“Were he to be confirmed without this allegation being firmly disproved, it would hang over his future decisions on the Supreme Court for decades and further divide the country.”

The magazine’s reversal is significant given Mr Kavanaugh has repeatedly cited his Roman Catholic faith and his years as a student at the Jesuit-run Georgetown Prep school in Maryland.

Former president George W. Bush has been advocating for Mr Kavanaugh with wavering senators in recent days, according to a person familiar with Mr Bush’s outreach.

Mr Trump is publicly standing by his nominee.

“His testimony was powerful, honest and riveting,” he tweeted late on Thursday.

“The Senate must vote!”

Several Democratic Judiciary Committee members walked out of Friday’s hearing on Mr Kavanaugh’s nomination.

The fiercely-partisan debate saw Democrats clash with Republicans as Mr Trump tries to get his second nominee confirmed on the body that has the final word on key issues such as abortion and same-sex marriage.

Mr Trump successfully nominated Neil Gorsuch for the vacancy created by the death of Antonin Scalia after Mr Trump’s predecessor Barack Obama had failed to get his candidate, Merrick Garland, confirmed.

Now Mr Trump wants Mr Kavanaugh to fill the berth vacated by the retiring Anthony Kennedy.