U.S. Sen. Todd Young has joined a growing chorus of Republicans calling on embattled Alabama GOP Senate candidate Roy Moore to drop out of the race.

Moore has been accused of having sexual contact with two teenage girls and pursuing three others decades ago. But so far he has denied the allegations, first reported by The Washington Post, and has said he does not plan to drop out of the Alabama Senate race.

Young, the freshman senator from Indiana, said in a series of tweets Monday that the allegations “remain far more persuasive” than Moore’s denials.

Young said that disqualifies Moore from serving in the Senate. He also said that if Moore does not step aside, the Senate will “need to act” to protect its integrity.

Indiana’s other U.S. senator, Democrat Joe Donnelly, sent an email to supporters on Sunday night, asking them to donate to the campaign of the Democrat running against Moore in a Dec. 12 special election in Alabama.

“My top priority as a senator is to look out for Hoosiers. But I need partners who will put common-sense ideas above partisanship — partners like Doug Jones, the Democratic candidate running against Roy Moore in Alabama’s Senate race,” the email said.

“I know Doug will work alongside me to fight on the issues that matter to Hoosiers because that’s who he is at his core. As the son of a steelworker, Doug understands the value and dignity that comes with a good-paying job,” it said.

Donnelly’s message referred to Moore as an extremist with a record of putting political ideology above the rule of law. It did not mention the sexual allegations against Moore which have come to light recently.

Moore has said he is the victim of a “witch hunt,” vowing to stay in the race.

The Associated Press contributed to this report.