LOUISVILLE, Ky.  —  Democrat Daniel Mongiardo (search) has cut into the comfortable lead that incumbent U.S. Sen. Jim Bunning (search) held just a month ago in their bitterly fought contest, according to a Bluegrass Poll released Sunday.

The poll, published in The Courier-Journal of Louisville, showed Bunning is apparently leading by 6 percentage points. However, the poll's margin of error was plus or minus 3.7 percentage points.

A similar poll taken in September showed a 17-point lead for Bunning, who is seeking his second term in the Senate.

The race has made national headlines in recent weeks as the two have traded barbs.

Bunning has compared his rival's appearance to one of Saddam Hussein's sons, and said his wife was "black and blue" because Mongiardo's staff assaulted her at a summer picnic. Bunning apologized for the Hussein comment and Mongiardo denied the assault allegation.

Bunning has accused Mongiardo of spreading "disgusting" rumors that he is mentally incompetent. Mongiardo denied Bunning's accusation as "just another absurd comment," but questioned what he called his opponent's "bizarre conduct."

The new poll, conducted by phone on Monday through Wednesday, found 49 percent of likely voters would vote for Bunning and 43 percent prefer Mongiardo. Nine percent were undecided. Numbers do not add up to 100 percent because of rounding.

The Bluegrass Poll taken Sept. 10-15 found 51 percent of voters supported Bunning, 34 percent were for Mongiardo and 15 percent were undecided.