"This path is not the one that I would have chosen for Missourians or my colleagues", said Missouri House Speaker Todd Richardson, a Republican.
Although lawmakers gathered more than the constitutionally required signatures of three-fourths of the members of each chamber to summon themselves into a special session, some wavered before finally agreeing to the plan.
Per the state Constitution, after the legislative session there are only two ways for the legislature to return: the governor calls a special session, or the House and Senate have a majority vote to hold a special session. The only state official to be ousted by impeachment was Missouri Secretary of State Judi Moriarty in 1994.
Greitens also faces a felony charge of computer data tampering for allegedly using a donor list from the veterans' charity he founded, The Mission Continues, to raise money for his 2016 gubernatorial campaign. Two staffers said they abided by Greitens' multiple orders to share the list, which The Associated Press reported yielded nearly $2 million in donations to the campaign.
Greitens, a former U.S. Navy Seal commando and onetime rising star in the Republican Party, has come under mounting pressure from Missouri politicians of both parties to resign since becoming embroiled in a sex scandal stemming from an admitted extramarital affair with a hairdresser.More news: Opry Mills shooting: Man fatally shot at Nashville, Tenn. mall
The triple-A-rated state's revenue collections for fiscal 2018 at $7.8 billion are up 2.1% from $7.64 billion previous year, state budget director Dan Haug said in the latest general revenue report through April.
Greitens has been accused of taking a nonconsensual nude photo of a woman he was having an affair with.
The session could lead to an impeachment, which would be a first for a Missouri governor, according to the St. Louis Post-Dispatch.
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.
Several lawmakers signed the petition then crossed out their names.More news: John Peterson soars into Quail Hollow lead behind pair of eagles
In the filing, Greitens' attorney specifically points to the release this week of the House committee's report about the donor list.
Greitens has denied blackmailing the woman and has called the investigation a "political witch hunt".
Pro Tem Richard tells reporters this process "has monumental consequences".
That committee found Greitens illegally used the list in his campaign.More news: Europa League: Wenger slammed for Arsenal's 1-0 loss to Atletico Madrid