Republican Senate leaders announced in a press conference on Wednesday that after he was confronted with the allegations, Sen. John McGee (R) said that he would immediately resign.
"In this situation, my first priority is to ensure a safe, secure and professional work environment for Senate employees," said Senate President Pro Tem Brent Hill, the Magic Valley Times-News reports. "My second priority is to protect the integrity and institution of the Idaho State Senate."
"Sen. John McGee does not admit any wrongdoing," Hill added. "I have requested the attorney general's office to further review the matter. We also express our compassion to John McGee's family, and most particularly his wife."
The attache, who is not a minor, has so far been unidentified, and is on paid leave.
McGee, who was serving his fourth term and was also chair of the Canyon County Republican Central Committee, was arrested last June for allegedly drunkenly stealing and driving a Ford Excursion, and then jack-knifing it in a stranger's driveway. He was initially charged with felony grand theft, but reached a plea agreement that left him with a misdemeanor DUI.