Image copyright Researchgate.net/ Getty Image caption Brett Kavanaugh denies the allegations by Christine Blasey Ford

The woman who accuses US Supreme Court nominee Brett Kavanaugh of sexual assault has been given extra time to decide whether she will testify against him at a confirmation hearing.

Allegations from a university professor, Christine Blasey Ford, emerged in the US media last week.

She gave details of an incident which she says happened at a party in 1982.

Her lawyer has accused Republicans of trying to "bully" her with "arbitrary" and "aggressive" deadlines.

The Friday deadline given by the Senate judiciary committee is now reported to have been switched to later on Saturday.

President Donald Trump attacked Prof Ford's credibility on Friday, saying if the attack had been "as bad as she says", she would have reported it to the authorities sooner.

Judge Kavanaugh has repeatedly denied the allegations.

Why the change in deadline?

Prof Ford insists she is ready to testify at the hearing, but negotiations over certain conditions she has set out, including it not taking place until next Thursday, have delayed proceedings.

The committee originally granted her a deadline of 22:00 on Friday (02:00 GMT Saturday) to agree to revised terms - though it is not yet known what these are.

But the professor's lawyer, Debra Katz, demanded another day to decide, saying: "Its sole purpose is to bully Dr Ford and deprive her of the ability to make a considered decision that has life-altering implications for her and her family."

In response, Senator Chuck Grassley - the lead Republican on the committee - said he had granted Prof Ford "another extension" - which, according to the New York Times, runs until 14:30 on Saturday (18:30 GMT).

Skip Twitter post by @ChuckGrassley Judge Kavanaugh I just granted another extension to Dr Ford to decide if she wants to proceed w the statement she made last week to testify to the senate She shld decide so we can move on I want to hear her. I hope u understand. It’s not my normal approach to b indecisive — ChuckGrassley (@ChuckGrassley) September 22, 2018 Report

How did the allegations come to light?

The allegation against Judge Kavanaugh, President Donald Trump's pick for the US top court, became public last week.

It emerged Prof Ford had detailed the alleged assault in a confidential letter to the top Democratic senator on the judiciary committee, Dianne Feinstein, in July.

As the judge neared confirmation, news about the letter leaked to US media. Ms Feinstein then confirmed she had passed it onto the FBI.

After days of continued media speculation, Prof Ford went on record in a Washington Post article as the mystery accuser, detailing the alleged assault.

Media playback is unsupported on your device Media caption Why it can take sexual assault allegations years to come out

She said Mr Kavanaugh tried to drunkenly remove her clothing at a party, pinned her to a bed and covered her mouth when she was 15 and he was 17.

Since then, her lawyers have been in a back-and-forth with the judicial committee, trying to agree on terms for her to testify.

She had asked for a number of preconditions, including not testifying with Mr Kavanaugh in the room and the subpoenaing of his friend, Mark Judge, who she said witnessed the alleged attempted rape.

Some Republicans, including President Trump, have accused her and Democratic politicians of deliberately trying to delay and obstruct the judge's confirmation, and urged them to push forward.

The feelings are strong on both sides - with both Prof Ford and Brett Kavanaugh and his wife both receiving threats and rallies of support over the matter.

Media playback is unsupported on your device Media caption Alumni of Ford's school: 'We believe her'

Why is the hearing important?

The choice of a new justice for the Supreme Court is pivotal, as it often gives the final word on highly contentious laws and its nine judges have an immense impact on US public life.

As Mr Trump's pick, Brett Kavanaugh has to first be approved by the Senate before he can take his seat - but before that vote can happen, he has to be approved by the judiciary committee, where Prof Ford may testify.

The Senate is made up of 51 Republicans and 49 Democrats - so any testimony she gives on the allegations could prove pivotal.

Some have said there should not be a vote on his confirmation until Prof Ford has been heard.

What has Mr Trump said?

President Trump weighed in heavily on the allegations on social media on Friday.

In a series of tweets, he questioned why law enforcement was not called at the time of the alleged assault, in 1982.

Skip Twitter post by @realDonaldTrump I have no doubt that, if the attack on Dr. Ford was as bad as she says, charges would have been immediately filed with local Law Enforcement Authorities by either her or her loving parents. I ask that she bring those filings forward so that we can learn date, time, and place! — Donald J. Trump (@realDonaldTrump) September 21, 2018 Report

He also reiterated his full support for Judge Kavanaugh who he described as a "fine man, with an impeccable reputation".

Mr Trump's controversial comments were criticised by Democratic politicians and some Republicans.

Republican Senator Susan Collins said she was "appalled" by Mr Trump's tweet.

"We know that allegations of sexual assault - I'm not saying that's what happened in this case - but we know that allegations of sexual assault are one of the most unreported crimes that exist," she told reporters.

Only 23% of rapes and sexual assaults are reported to the police, according to the Department of Justice's 2016 report.

On Friday, the hashtag #WhyIDidntReport trended on Twitter, with thousands sharing personal stories of sexual harassment and assault.

Patti Davis, the daughter of President Ronald Reagan, wrote in the Washington Post that she was raped 40 years ago.

"It doesn't surprise me that for more than 30 years, Christine Blasey Ford didn't talk about the assault she remembers," she wrote, adding: "It's important to understand how memory works in a traumatic event."