Missouri Gov. Eric Greitens speaks at a news conference April 11 in Jefferson City, Mo. (Julie Smith/Jefferson City News-Tribune/AP)

Missouri state lawmakers on Thursday called a special session to consider impeaching embattled Republican Gov. Eric Greitens.

The announcement from the Republican-held House and Senate comes as Greitens, a former Navy SEAL once considered a rising star in his party, faces widespread calls to step down amid criminal charges.

The governor faces a trial this month on a felony invasion-of-privacy charge for allegedly taking an unauthorized, nude photo of a blindfolded woman with whom he was having an extramarital affair. Last month, Greitens was also charged with two felony counts of computer tampering stemming from allegations that he used a veterans charity donor list to raise funds for his 2016 campaign for governor without the permission of the group, which he founded.

It is the first time in Missouri’s history that state legislators have called for a special session, House Speaker Todd Richardson (R) said in a news conference Thursday. The special session is set to begin on May 18, just days after the start of Greitens’s criminal trial, and will last no more than 30 days. It will allow lawmakers to continue investigating the governor’s conduct and consider taking disciplinary action against him, Richardson said.

“This path is not the one that I would have chosen for Missourians or my colleagues,” Richardson said. “I have hoped from the beginning of this process that the committee would find no wrongdoing so that we could bring this investigation to a close. … Unfortunately this is where the facts led.”

Greitens, a married father with two children, admitted in January to having an affair before he ran for governor. But he has denied any criminal activity and declined to testify before a House committee. The defiant governor has showed no signs that he is preparing to leave office claiming, like President Trump, that he is the target of a “witch hunt.” He has asserted that his criminal trial this month will exonerate him.

The House has already released two scathing reports against the governor. The first provided dramatic evidence of an extramarital affair with Greitens’s former hairdresser, who the committee deemed a “credible witness.” The woman testified that in 2015, before Greitens’s gubernatorial run, he groped her, slapped her and threatened to blackmail her. She alleged that he blindfolded her and taped her hands to exercise equipment and that she felt “coerced” to perform oral sex on him.

The second House report, released Wednesday, detailed allegations that Greitens used a donor list from a private charity to raise campaign funds, lying about it to the state’s ethics commission.

In response to the report, the governor released a statement on Facebook from Catherine Hanaway, legal counsel to his campaign and former speaker of the Missouri House. The report “does a tremendous disservice to the U.S. and Missouri Constitutions,” the statement read. “Even though the report alleges that a false campaign report was filed, the Chairman did not allow the campaign an opportunity to be heard. He never asked the campaign to testify before his committee, nor did he request that the campaign provide any documents to his Committee.”

Richardson on Thursday disputed this, saying that from the beginning, the House committee “has made itself available” to testimony from the governor, welcoming any documents and witnesses from his legal team. “So the assertion that the committee has not done its work in reviewing all the evidence is not something I agree with.”

Richardson said the session will give lawmakers “the time it needs to conduct a fair, thorough and timely investigation” without being halted by the end of regular session.

“We will not avoid doing what is right just because it is hard or just because it was not the path we hoped to travel,” Richardson said. “Therefore we have taken the unprecedented step to continue to follow the facts wherever they may lead.”

The petition to hold a special session was signed by 138 members of the state House and 29 in the Senate, well over 80 percent of both chambers, said State Sen. Ron Richard (R), president pro tem of the Missouri Senate.

The session could lead to an impeachment, which would be a first for a Missouri governor, according to the St. Louis Post-Dispatch. The only state official to be ousted by impeachment was Missouri Secretary of State Judi Moriarty in 1994.

If the House votes to impeach Greitens, the Senate would then appoint a panel of seven judges to conduct a trial on whether to remove him from office, according to the Associated Press.

Richardson said he already spoken with retired judges about the process of preparing a potential trial panel.

“We stand ready to do it if called upon,” he said.

Greitens’s political crisis began in January. Following the initial news reports about the allegations, the governor became the target of investigations by the state attorney general, a St. Louis prosecutor and a house committee.

All of Missouri’s top Republican and Democratic leaders, in addition to Greitens’s top private donor, have called on him to step down. But Greitens has refused to budge. After being charged with computer tampering last month, he accused the prosecutor of wasting taxpayer money.

“I will have my day in court. I will clear my name. This prosecutor can come after me with everything she’s got, but as all faithful people know: In time comes the truth. And the time for truth is coming,” he said in a statement.

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