Former New York City Mayor Rudy Giuliani is challenging the basis of a federal raid on his home. Giuliani said Thursday night that the search warrant executed by FBI agents early Wednesday states that he failed to file with the Department of Justice (DOJ) for representing a Ukrainian national or office. “I never represented a Ukrainian national or official before the United States government. I’ve declined it several times. I’ve had contracts in countries like Ukraine. In the contract is a clause that says I will not engage in lobbying or foreign representation. I don’t do it because I felt it would be too compromising,” Giuliani, who was former President Donald Trump’s personal lawyer, said during an appearance on Fox News’s “Tucker Carlson Tonight.” Not registering with the DOJ would violate the Foreign Agent Registration Act. Giuliani used to represent Lev Parnas, a Ukrainian national who was later charged with campaign …