JEFFERSON CITY, Mo. -- In a historic move, Missouri lawmakers announced Thursday they are calling themselves into a special session to consider impeaching Gov. Eric Greitens following allegations of sexual misconduct and misuse of charity resources. The petition calls upon lawmakers to consider "disciplinary actions" against Greitens, which also could include lesser reprimands than impeachment.

House and Senate leaders said they had gathered more than the constitutionally required signatures of three-fourths of the members of each chamber to summon themselves into a special session that will start at 6:30 p.m. on May 18 -- just 30 minutes after the end of work in their regular session.

It will mark the first time in Missouri history that lawmakers have called a special session. Extraordinary sessions typically are called by governors.

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

Only one other Missouri official -- former Secretary of State Judi Moriarty in 1994 -- has been removed from office following impeachment.

The legislative announcement about a special session came a day after a House investigatory committee released a report indicating that Greitens had misused a donor list from a veterans' charity he founded to raise money for his 2016 gubernatorial campaign. The report included testimony from a former Greitens' aide indicating the campaign also falsely identified the source of the donor list in a settlement with the Missouri Ethics Commission.

It was the second stunning report from the House panel. Last month, it released a report with testimony from a woman alleging that Greitens had restrained, slapped, shoved, threatened and belittled her during a series of sexual encounters in 2015 that at times left her crying and afraid.

Greitens faces a May 14 trial in St. Louis on a felony invasion of privacy indictment stemming from his encounter with the woman. He is accused of taking and transmitting a partially nude and unauthorized photo of the woman while she was bound and blindfolded in the basement of his home. Greitens has acknowledged having a consensual affair but has denied criminal wrongdoing.

In April, Greitens insisted he would not resign and said he would found not guilty.

"I will not be resigning the Governor's office. In three weeks, this matter will go to a court of law -- where it belongs and where the facts will prove my innocence," Greitens said on April 18. "Until then, I will do what the people of Missouri sent me here to do: To serve them and work hard on their behalf."

Two days later, he also was charged in St. Louis with a felony charge of tampering with computer data for allegedly disclosing The Mission Continues donor list to a political fundraiser in 2015 without the permission of the St. Louis-based veterans' charity that he had founded.