WASHINGTON — A growing chorus of Senate Republicans including Majority Leader Mitch McConnell, R-Ky., have called on Senate candidate Roy Moore to withdraw from a special election in Alabama if allegations prove true that the former judge initiated a sexual encounter with a 14-year-old girl nearly four decades ago.

“If these allegations are true, he must step aside,” McConnell said in a formal statement on behalf of all Republican senators.

Other Republican senators weighing in included Susan Collins of Maine, Jeff Flake of Arizona, David Perdue of Georgia, John Thune of South Dakota, Lisa Murkowski of Alaska, Cory Gardner of Colorado, Richard Shelby of Alabama and Patrick Toomey of Pennsylvania. Sen. John McCain, R-Ariz., called on Moore to step aside as well – and without couching his statement with “if true” language.

“The allegations against Roy Moore are deeply disturbing and disqualifying,” McCain said. “He should immediately step aside and allow the people of Alabama to elect a candidate they can be proud of.”

Moore has denied the allegations and given no indication that he will exit the race. “He has told me that it is absolutely false, and he is working on his campaign,” said Dean Young, a longtime friend and adviser to Moore, who has spoken to him since the allegations surfaced. “You all do what you are going to do, and we are going to stand in Alabama and fight for what is right and what is just.”

The state Republican Party has the power to disqualify Moore from the election, though it is too late to remove his name from the ballot, according to the Alabama secretary of state. McConnell and other Republicans will face the challenge of figuring out what candidate would run in Moore’s place – and how to win an election in which it is too late to replace the former judge’s name on the Dec. 12 ballot.

Under Alabama state law, the ballot cannot be changed within 76 days of an election. But a candidate can still withdraw. The state party can also request to disqualify a candidate on the ballot, even if the candidate wants to stay in the race.

In the event of either disqualification or withdrawal, the appropriate state canvassing boards would not certify any votes cast for Moore.

Alabama state law does allow write-in votes to be cast in general elections, as long as the names are for living people and written in without using a rubber stamp or stick-on label. Despite a state law barring candidates from appearing twice on ballots in the same election cycle, Sen. Luther Strange, R-Ala., who lost in the primary to Moore, would be an eligible write-in candidate, said John Bennett, an official at the state secretary of state’s office.

A group close to McConnell that spent millions to oppose Moore in the primary called on Gov. Kay Ivey and the state party to investigate the allegations. “If there’s even a shred of evidence to these accusations, Gov. Ivey and the Alabama Republican Party need to do everything in their power to remove Judge Moore from the ballot,” said Steven Law, the CEO of the Senate Leadership Fund. “There is no place in our party for sexual predators.”

Strange avoided reporters’ questions in the Capitol Thursday, but his Alabama colleague, Sen. Richard C. Shelby, said: “Luther Strange is a good senator, he’s a friend, and I support him. I don’t know what he’s going to do, but we’ll see what develops.”

The Washington Post published an extensive report Thursday describing Moore’s relationships with the then-14-year-old and three other girls he pursued when they were between the ages of 16 and 18.

Former Alabama Chief Justice and U.S. Senate candidate Roy Moore made inappropriate advances and had sexual contact with a 14-year-old girl when he was in his 30s, according to a story in The Washington Post. Associated Press/Brynn Anderson

None of the women sought out The Post. While reporting a story in Alabama about supporters of Moore’s Senate campaign, a Post reporter heard that Moore allegedly had sought relationships with teenage girls.

Over the ensuing three weeks, two Post reporters contacted and interviewed the four women. All were initially reluctant to speak publicly but chose to do so after multiple interviews, saying they thought it was important for people to know about their interactions with Moore. The women say they don’t know one another.

The news struck the Capitol with a thunderbolt on Thursday afternoon. As senators headed in for an afternoon vote on a Transportation Department nominee, reporters swarmed Republicans in a bid to get their reaction.

McConnell, R-Ky., was hounded more than usual as he headed to the Senate Chamber, with reporters shouting questions at a lawmaker they know usually stays mums when asked questions in the hallway.

Once he stepped on to the floor, McConnell quickly voted and conferred with aides. Moments later, Strange came to the floor and headed straight for McConnell. They conferred for several moments before McConnell asked an aide to track down his top spokesman, Don Stewart.

“You can’t make this up,” mouthed one of McConnell’s aides to another colleague.

Stewart came to the floor and told McConnell and Strange that a statement was being sent to reporters. In it, McConnell called on Moore to step down if the allegations are true.

Strange, seemingly unsure of what to do, was instructed to vote and leave the chamber as quickly as possible.

McConnell then conferred with other senators, including Rob Portman, R-Ohio, Thom Tillis, R-N.C., and John Thune. Stewart also assured the senators that a statement was out but then, realizing that reporters were watching from above, instructed McConnell, “Please go.”

He walked toward the back door of the Senate Chamber, paused momentarily, and stepped out. Several reporters were waiting for him in the Ohio Clock Corridor.

McConnell’s inner circle spent late Thursday morning discussing the repercussions and how Republicans should move forward – and grousing that if Strange, their preferred candidate in the primary, was still the nominee, they would not be answering questions about Moore’s conduct.

“If it’s true, the Republican Party doesn’t have any place for pedophiles and he should step down immediately,” said Josh Holmes, a longtime McConnell confidant and his former chief of staff. “Steve Bannon is responsible,” he added about the McConnell foil and former White House chief strategist, for enabling candidates such Moore who are out of the Republican mainstream.

That view was shared by Scott Reed, a political strategist for the U.S. Chamber of Commerce, who opposed Moore’s nomination. “Here we go – another Steve Bannon special,” Reed said.