Sen. Ted Cruz on Monday withdrew his endorsement of Alabama Republican Senate candidate Roy Moore after a new woman came forward with accusations that Moore sexually assaulted her when she was a teen.

"I am not able to urge the people of Alabama to support his candidacy so long as these allegations remain un-refuted," Cruz told the Washington Examiner. "Both last week and this week, there are serious charges of criminal conduct that if true, not only make him unfit to serve in the Senate but merit criminal prosecution."

Cruz added that Alabama faced "an untenable choice," and implored Moore to immediately drop out of the race if the accusations were true.

"The people of Alabama deserve to have the option of voting for a strong conservative who has not committed criminal conduct," he said. "If these allegations are not true, then Judge Moore needs to come forward with a strong, persuasive rebuttal demonstrating that they are untrue."

Beverly Young Nelson on Monday became the fifth woman to come forward to claim Moore engaged in inappropriate behavior with her in the late 1970s when she was 16 and he was in his thirties.

At a press conference, Nelson showed TV cameras Moore's alleged yearbook inscription from late 1977.

"Grown men don't typically sign high school girls' yearbooks," Cruz continued. "As the father of two young daughters, this is a disquieting allegation, but let me repeat Judge Moore is entitled to present a defense."

Moore has vehemently denied any wrongdoing. But of the five GOP senators who threw their support behind the controversial, populist figure, only Sen. Rand Paul, R-Ky, continues to endorse him.

Moore's special election for U.S. Attorney General Jeff Session's old seat against Democratic nominee Doug Jones is set for Dec. 12.