Secretary of State Scott Gessleron Wednesday filed suit in court to halt an investigation by the state’s Independent Ethics Commission into whether he misspent state funds.

In court papers, Gessler’s attorneys argue that the ethics commission has exceeded its legal authority because the complaint against him doesn’t involve influence peddling and the panel has no jurisdiction in criminal matters.

Lawyers for Gessler, a Republican, also said the ongoing investigation is injuring the secretary of state’s reputation.

“The secretary will suffer irreparable harm, as the commission has hauled him in before the tribunal, subjected him to evolving and substandard procedures, and forced him to respond to criminal (or some other unspecified legal) allegations over which the commission clearly has no jurisdiction,” the lawsuit said. “This illegal assertion of jurisdiction also has harmed or will harm the secretary’s reputation and his ability to carry out his official duties as he sees fit.”

Gessler’s legal action comes just days before the commission is expected to issue a report Monday of its findings into whether he spent state funds for political purposes by using money from his discretionary fund and office budget to attend a conference last year of the Republican National Lawyers Association in Florida and then attending the Republican National Convention taking place nearby.

A complaint filed by the left-leaning Colorado Ethics Watch alleges Gessler’s spending on the trip violates prohibitions on the use of state funds for political purposes. The group also filed a complaint with the commission alleging that Gessler misused state funds by giving himself an end-year-payout from his disrectionary fund and submitting no receipts for it.

But Ethics Watch didn’t stop there. The group also asked Denver police to investigate, and Denver District Attorney Mitch Morrissey’s office launched a criminal probe of Gessler’s actions that is still underway.

Gessler was reimbursed $1,452 from his office’s discretionary account for the trip, which was submitted to his office as “RNLA/RNC Trip.” His office also paid $422 out of its regular budget for a flight change to bring him home a day early, something he said was needed because of threats against his family.

Gessler also sought and received $1,400 from the fund in July of 2011 at the end of the 2010-11 fiscal year. The request, for which Gessler submitted no receipts, drained what was left in the fund that year.

Colorado Ethics Watch said it couldn’t file a complaint with the commission over that action because it was beyond a one-year statute of limitations. However, the group did file a complaint with the commission over a $117 payout — also with no receipts — Gessler took from the fund in July of 2012, well within the statute of limitations.

His attorneys, however, said there has never been a clear allegation as to which specific provisions of law Gessler is accused of violating.

“It is unclear what fiscal rules, statute, or constitutional provision to which the investigator refers, nor is it clear how the commission would even have jurisdiction,” Gessler’s attorneys said in court papers. “CREW’s (Ethics Watch’s) complaint never cited any such fiscal rule, statute, or constitutional provision, nor has the commission subsequently provided it to the secretary.

“In fact, the standard against which the secretary must now defend himself remains unclear more than three months after CREW submitted its complaint – and more than a month after the Dec. 20, 2012, commission deadline for the secretary’s response.”

Officials with the ethics commission declined comment on the lawsuit.

The commission also Monday is scheduled to consider a request from Gessler’s office that he be allowed to create a legal defense fund and take donations for it.

Tim Hoover: 303-954-1626, thoover@denverpost.com or twitter.com/timhoover