The top Republican in the Senate said Monday that candidate Roy Moore should quit his Alabama race amid allegations he had sexual contact with a 14-year-old girl and pursued romantic relationships with other teenage girls decades ago.

"I believe the women," said Majority Leader Mitch McConnell.

The Kentucky Republican said flatly that Moore should step aside for another candidate days after the Washington Post report that rocked the campaign for what the Republicans had considered an inevitable special election win on Dec. 12. When the story first broke last Thursday, McConnell had said Moore should step aside if the allegations were true.

Another Alabama woman came forward at an emotional news conference with high-profile attorney Gloria Allred a few hours after McConnell's comments to accuse Moore of sexual assault.

Beverly Young Nelson said she was "terrified" during an incident she said occurred when she was 16.

'I don't even know the woman'

Moore called a news conference in Gallant, Ala., after the new allegations were made public.

"I can tell you without hesitation this is absolutely false. I never did what she said I did. I don't even know the woman," Moore said.

He signalled he has no intention of ending his candidacy, calling the latest charges a "political manoeuvre" and launching a fundraising appeal to "God-fearing conservatives."

USA-CONGRESS/MOORE

Beverly Nelson, left, reads a statement to reporters with lawyer Gloria Allred during a news conference in New York on Monday, announcing new allegations of sexual misconduct against Alabama Republican congressional candidate Roy Moore. (Lucas Jackson/Reuters)

Nelson said she was working at a restaurant and that Moore, then the district attorney for Etowah County, was a regular customer.

The alleged assault occurred when she accepted a ride from Moore. Nelson said he stopped the car in a dark area and proceeded to grope her breasts and force her head towards his torso.

"I thought he was going to rape me," she said. Nelson was able to fend him off, she said, and was left in the area to find her own way home.

'I thought he was going to rape me': Alabama woman talks about Roy Moore4:44

She said she suffered severe bruising on her neck and soon quit her restaurant job in order to avoid Moore.

Moore had emphasized no one would believe her if she came forward, stressing she was a "a child." Nelson said at various points later in her life she told her sister, mother and husband about the incident.

Nelson stressed that she voted for Donald Trump in last year's election, hoping to pre-empt criticism that her story was politically motivated.

Allred said Nelson is willing to testify under oath at any Senate judiciary committee called to investigate the Moore allegations.

Moore called the accusations a "witch hunt" in a statement released shortly before the news conference. He has said he plans to file a lawsuit over the initial Post report that has threatened to derail his Senate bid.

While pressure to quit the race four weeks before Election Day intensified from within the Republican Party, Moore assured supporters Sunday night at a Huntsville, Ala., gym that the article was "fake news" and "a desperate attempt to stop my political campaign."

Politically motivated accusations, Moore says

Moore said allegations that he was involved with a minor child are "untrue" and said the newspaper "will be sued," drawing a round of applause. The former judge also questioned why such allegations would be levelled for the first time so close to the special election in spite of his decades in public life.

"Why would they come now? Because there are groups that don't want me in the United States Senate," he said, naming the Democratic Party and the Republican establishment and accusing them of working together. He added, "We do not plan to let anybody deter us from this race."

The Post story quoted four women by name, including the woman who alleged the sexual contact at 14, and had two dozen other sources. 

 Moore, too, has tried to raise money from the controversy, writing in a fundraising pitch that the "vicious and sleazy attacks against me are growing more vicious by the minute."

McConnell, questioned at a tax event in Louisville on Monday, said a write-in effort by another candidate was a possibility.

"That's an option we're looking at ... whether or not there is someone who can mount a write-in campaign successfully," McConnell said. Asked specifically about Luther Strange, the loser to Moore in a party primary, he said, "We'll see."

McConnell

Senate Majority Leader Mitch McConnell, a Republican from Kentucky, said he believes the women who have come forward to accuse Roy Moore. (J. Scott Applewhite/Associated Press)

Strange was backed by Trump in the primary race, while Moore received support from former Trump adviser Steve Bannon.

Doug Jones, the Democratic Party candidate in Alabama's Senate race, says that Republican Roy Moore will be "held accountable by the people of Alabama."

In a Jones' campaign statement issued Monday, "the courage" of Moore's accusers was applauded.

Moore and Jones face a Dec. 12 special election to replace Strange, who was appointed to replace Jeff Sessions when Sessions was named U.S. attorney general.

Mosts of the public opinion polls that were conducted since the Washington Post story was published show Moore leading.

Senate could expel Moore if he runs, wins

Even if Moore were to step aside, his name would likely remain on the ballot. And any effort to add Strange as a write-in candidate would threaten to divide the GOP vote in a way that would give the Democratic candidate a greater chance of winning.

Should Moore still win, the head of the Senate Republican campaign committee said Monday the Senate should vote to expel him.

Sen. Cory Gardner of Colorado said in a statement that he believes the women who accused Moore of sexual misconduct and that they spoke with "courage and truth."

Gardner said what they recounted proves Moore is unfit to serve in the Senate and should not run for office.

Prior to the Nelson news conference, Alabama's governor was still on Moore's side. Kay Ivey said Monday she plans to vote for Moore, but added that "there may be some more facts to come out."

Moore, 70, courted controversy long before the recent allegations. The former chief justice of Alabama urged judges to defy a Supreme Court on gay marriage, said he believed former president Barack Obama is not U.S.-born, and once wrote an op-ed stating that Democrat Keith Ellison shouldn't take the congressional oath because he is a practising Muslim.

While Moore has called the allegations "completely false and misleading," in an interview with conservative radio host Sean Hannity he did not wholly rule out dating teenage girls when he was in his early 30s. Asked if that would have been usual for him, Moore said, "Not generally, no."

The situation has stirred concern among anxious GOP officials in Washington in a key race to fill the Senate seat once held by Sessions. Losing the special election to a Democrat would imperil Republicans' already slim 52-48 majority. But a Moore victory also would pose risks if he were to join the Senate Republicans under a cloud of sexual misconduct allegations.

With files from CBC News