Illinois GOP Senate hopeful Mark Kirk said Thursday morning that Democratic rival Alexi Giannoulias announcement at Wednesday's debate that he would only run positive ads in the last week of the campaign was a "cynical" ploy because the Senate Democratic campaign operation is "doing his dirty work."

"This move is very cynical," Kirk said to reporters after a town hall session with Navistar employees at the Navistar World headquarters in Warrenville, in DuPage County, a mother lode of GOP votes.

"It's just a few days to go. He is letting the Democratic Senatorial Campaign Committee do his dirty work. ...I think his move is very cynical knowing that Sen. (Bob) Menendez and the Democratic Senatorial Campaign Committee is doing his dirty work," Kirk said. Menendez is the New Jersey senator who is the chair of the DSCC, which is pouring millions into ads--many negative against Kirk--to bolster Giannoulias.

The Republican Senate political shop, the National Republican Senatorial Committee is not spending as much as the DSCC is in Illinois because Kirk is being helped by outside groups allied with the GOP, including the U.S. Chamber of Commerce and groups linked to GOP political guru Karl Rove.

"...We only have a couple days to go and to try to grandstand on this issue having waged an almost entirely negative campaign ....it's seen as cynical knowing that the Democratic Senatorial Campaign is going to do his dirty work," Kirk said.