(CNN) - The Republican vying for President Barack Obama's former Senate seat admitted he has previously mischaracterized an aspect of his lengthy service in the United States Navy.
The admission Sunday came after Kirk's opponent in the divisive Senate race, Democrat Alexi Giannoulias, raised questions with the Washington Post about the Intelligence Officer of the Year Award Kirk claimed to have received during his service in the Kosovo conflict 10 years ago.
In a post on his blog Sunday, Kirk said he and his staff discovered last week that they had inadvertently misidentified the award in his official biography and on other occasions. Kirk was instead issued the Rufus L. Taylor Intelligence Award – an honor Kirk said is as distinguished as that of Intelligence Officer of the Year.
The National Military Intelligence Association, a professional group, issued Kirk and each member of his unit the award for "exceptional achievements of an outstanding Naval Intelligence career professional."
"My corrected biography accurately shows I received the United States Navy Rufus L. Taylor Intelligence Award – as the leader of an ad-hoc intelligence effort supporting four EA-6B Prowler electronic attack squadrons as part of Operation Allied Force – instead of Intelligence Officer of the Year. I accepted the Taylor Intelligence Award (named after the head of Navy intelligence in World War II) as the leader of an intelligence section that I assembled and led. There is no hierarchy between these awards as the Taylor Intelligence Award is equally distinguished," Kirk said.
Kirk has repeatedly referenced his more-than two decades of service in the Navy Reserves during the course of his Senate campaign, and the mistaken award appeared in both Kirk's congressional and campaign websites.
Giannoulias, the Illinois state treasurer, seized on the mischaracterization, calling the flap the latest proof Kirk is a "typical Washington politician."
But in his blog post Sunday, Kirk took aim at Giannoulias for raising questions about his service and called the attack a "disgrace."
"Our state and nation face serious problems – and having a veteran's military record challenged by a politician who never served and was anointed by the media as a 'mob banker' is absurd," Kirk wrote in reference to the fact the bank Giannoulias' family owned collapsed earlier this year costing the FDIC over $300 million.
It remains unclear what effect Kirk's admission may have on a Senate race that is already among the most bitterly-fought this cycle. The disclosure comes less than two weeks after Connecticut Democrat Richard Blumenthal apologized for repeatedly suggesting he served in Vietnam when in fact he served in the Marine Corps Reserves and was stationed stateside. But a Quinnipiac survey released shortly after Blumenthal's apology indicated the Connecticut Democrat had lost little support following his admission.
Meanwhile, recent polls in Illinois show the race is a dead heat.