"Mr. Craig used these funds converted from his campaign committee to pay legal expenses he incurred in connection with his arrest, guilty plea, and subsequent efforts to withdraw his guilty plea in Minnesota," according to the complaint. "These legal costs were not made in connection with his campaign for federal office or for ordinary and necessary expenses incurred in connection with his duties as a senator."

The federal officials also contented that Craig would have faced the expenses "irrespective of his duties as senator."

The government is also asking a judge to order the former senator to pay a fine and for the investigative costs surrounding the case.

Craig has maintained that he did not intend to solicit sex during the airport stop.

"Let me be clear, I am not gay. I never have been gay," Craig said during an August 2007 press conference. "I did nothing wrong at the Minneapolis airport. I regret my decision to plead guilty and the sadness that decision has brought to my wife, family, friends, staff and fellow Idahoans. For that I apologize."

The Idaho senator later said he would resign, but ultimately opted against doing so, deciding instead to simply not seek reelection in 2008.