Charges filed by the Kentucky Judicial Conduct Commission stem from an August incident in open court.
The charges were filed in February but not made public until Wednesday, after Popovich's response was filed.
They stem from an incident in open court in August, when Popovich was locked in a tight re-election race with Assistant County Attorney Cameron J. Blau.
On Aug. 5, while hearing motions to suppress evidence in a traffic stop case, Popovich accused Blau of improperly assisting the defense attorney, the commission said. The incident was recorded on video.
"You stated in open court that your grounds for this accusation were based, in part, on ex-parte hearsay statements made to you by attorneys who were not involved in the case at social gatherings outside of court. When Defense Counsel denied receiving any improper assistance, you accused him of lying in front of his client," the commission wrote in its notice to Popovich.
Judicial Conduct Commission Docket Entries