Judge Brett Kavanaugh and the woman who accuses him of sexually assaulting her at a teenage party 36 years ago are to appear before the Senate Judiciary Committee in a hearing which has electrified the United States.

Who are the witnesses?

Judge Kavanaugh, a 53-year-old federal appeals court judge, is President Donald Trump's nomination for the vacant seat in the US Supreme Court. Christine Blasey Ford, 51, is psychology professor at Palo Alto University in California.

What is the allegation against Judge Kavanaugh?

According to Prof Ford, Mr Kavanaugh assaulted her at a party in the 1980s when she was 15 and he was 17. She claimed that he pinned her to a bed, groped her and tried to pull off her clothes, covering her mouth with his hand when she tried to scream.

What is his response?

Mr Kavanaugh has said he "categorically and unequivocally" denies the allegation. Republicans have criticised the way the claims emerged shortly before his confirmation hearing, claiming they are part of a Democrat plot to derail his nomination.

Is this the only allegation against Mr Kavanaugh?

No. Since Prof Ford went public, two more women have come forward with claims of sexual misconduct during the 1980s. He has denounced them as "smears, pure and simple", saying there has been a last-minute "frenzy" to prevent his appointment.

Why is the case considered so important in the US?

Appointments to the Supreme Court are for life and, if Mr Kavanaugh is confirmed in the post, it will potentially lock in a conservative majority in the court for decades to come, shaping rulings on highly contentious issues including abortion, regulation and the environment.

Mr Trump's election pledge to nominate only conservatives to the court was seen as key to firing up his voter base, and rejection of Mr Kavanaugh would be a huge blow to the president.

What happens next?

The judiciary committee must vote on Mr Kavanaugh's confirmation before it goes to the full Senate - where the Republicans have a slender 51 to 49 seat majority - for a vote there.

The Republicans hope it will be settled by early next week, while the Democrats are pressing for a delay to allow the allegations against him to be fully investigated.