The candidate laughed when reporters asked for his response to one-time publishing powerhouse Judith Regan's $100 million lawsuit claiming that her former employers directed her to lie to federal investigators about Kerik because of the implications for Giuliani.
Giuliani was asked about the lawsuit while campaigning in Iowa on Wednesday, reports CBS News' Ryan Cosaro.
"I don't respond to the story at all, I don't know anything about it. It sounds to me more like kind of a gossip column story, more than a real story," Giuliani said. "I think that's a gossip column story. The last thing in the world you want to do while running for president is respond to gossip column type stories."
Asked if he was aware of Kerik and Regan's relationship, the former New York mayor said: "I think that's a gossip column story, and the last thing in the world you want to do when you're running for president is respond to gossip column type stories."
The Regan allegations are the latest issue related to Kerik to dog Giuliani just weeks before voting begins in the GOP nomination race. Last week, Giuliani's former police commissioner, business partner and friend pleaded not guilty to a 16-count federal indictment charging him with conspiracy, corruption and tax evasion.
Regan, who worked for HarperCollins Publishers LLC, says that "it is now widely accepted" that one of Giuliani's vulnerabilities is the 52-year-old Kerik. Because of Regan's affair with Kerik, court papers say, a senior executive at News Corp., HarperCollins' parent company, told her he believed she had information about Kerik that could hurt Giuliani's campaign and she should lie to federal investigators.
She also contends another executive told her to withhold documents that were relevant to the government's investigation of Kerik, and court papers say that HarperCollins and News Corp. "knew they would be protecting Giuliani if they could preemptively discredit her."
News Corp. calls the claims preposterous.
On other matters Wednesday, Giuliani:
Expressed disapproval of any outside advertising effort that might surface on his behalf akin to the one John McCain's supporters have launched in South Carolina. McCain has asked his donors not to bankroll such campaigns.
Asked whether he would make the same request of his backers should they launch such an effort, Giuliani said: "My donors aren't so that's not really a fair question. No one has suggested that there's any such thing going on on my behalf. I would not want to see such a thing going on on my behalf. I would never ask anybody to do that and I would ask people not to do that because all it does is confuse your race."
Countered Mitt Romney's criticism that Giuliani provided tuition breaks at the City University for illegal immigrants, saying: "the governor probably has the worst record on illegal immigration." He said the number of illegal immigrants in Massachusetts soared on Romney's watch while several cities provided sanctuary to undocumented foreigners.
"He did very little about it until the last day or two he was in office and it never had any impact. So, I think people are going to have to weigh how credible his claims are given his very poor record in that area," Giuliani said.