Missouri Gov. Eric Greitens speaks at a news conference Wednesday in Jefferson City, Mo. (J.B. Forbes/AP)

The pressure on Missouri Gov. Eric Greitens to resign escalated dramatically Thursday, with two state Republican leaders and a top donor joining the call for him to step down a day after the release of an explosive report alleging he initiated unwanted sexual contact with a woman who worked as his hairdresser.

A onetime rising national star, Greitens is now in his lowest standing among Republican officials and donors since taking office in early 2017, facing intense criticism and even talk of impeachment.

But Greitens has stood defiant, showing no sign that he is preparing to leave office. The governor said Wednesday, when the report was released, that he is the target of a “witch hunt,” echoing language President Trump has used to describe the special counsel probe into Russian interference in the 2016 election. Greitens has said that a separate criminal trial, scheduled for next month, will exonerate him.

David Humphreys, a top Greitens donor, was part of a chorus of powerful Republicans who urged him to step down Thursday. State Senate Majority Leader Mike Kehoe and U.S. Rep. Ann Wagner also said he should go.

A bipartisan state House panel released a report Wednesday that included detailed testimony from a woman they deemed a “credible witness.” The woman, Greitens’s former hairdresser, said that in 2015, he groped her and slapped her. She also said in testimony that he blindfolded her and taped her hands to exercise equipment and that she felt “coerced, maybe,” to perform oral sex on him.

Greitens has acknowledged having an extramarital affair but has denied engaging in any illegal conduct. He declined to testify before the state House committee.

The lawmakers initiated their probe after allegations surfaced that Greitens had photographed the woman naked without her consent, and a St. Louis prosecutor brought a felony invasion-of-privacy charge against him.

But the testimony revealed in the state legislative report has spurred leading Republicans not to wait until the outcome of that trial to urge Greitens to step down.

“These new revelations describe behavior that makes it impossible to retain confidence in his ability to govern wisely and well,” Humphreys said in a written statement.

Kehoe said he had “come to the conclusion that [Greitens’s] ability to lead is not going to be there.” He criticized Greitens for his “witch hunt” comment, saying it was “not the right position to be in at this time.”

Wagner wrote on Twitter that she was “disgusted, disheartened” and believes Greitens “is unfit to lead our state.”

On Thursday, Greitens was quiet on the subject. His office did not comment on the allegations or the calls for his resignation.

The comments from Humphreys, Kehoe and Wagner came a day after state Attorney General Josh Hawley called on Greitens to step down. Hawley is a top recruit running in the Republican primary to challenge Sen. Claire McCaskill (D) in a marquee contest in the larger national battle for the majority in the U.S. Senate.

McCaskill also called for Greitens to step down. “He is not in the position that he can lead the state of Missouri at a critical time in our state’s history,” she said Thursday, repeating her call from a day earlier for Greitens to leave office.

Hawley’s office has been investigating allegations that resources at Greitens’s former veterans charity were improperly used for his campaign. The special state House committee has also been looking into this issue, according to a transcript of its discussions released this week. The committee said it plans to issue a separate report on the matter.

State House Speaker Todd Richardson, a Republican, called the testimony in the report released Wednesday “beyond disturbing.” He said the committee voted to “expand their mission” to issue a recommendation of any disciplinary action the governor should face. Richardson said this would happen in a special session after the regular one concludes next month.

Responding to Greitens, Richardson said: “This is not a witch hunt.”

State House Minority Leader Gail McCann Beatty (D) said Greitens “must resign and, if he fails to do so, I believe, we should begin impeachment proceedings.”

Asked Thursday whether Greitens should step down, Republican Governors Association spokesman Jon Thompson said the organization had nothing to add to a February statement that indicated Greitens had stepped down from the RGA’s executive committee.

Sullivan reported from Washington.