Speaking to a crowd of about 100 at Stoney's Rockin' Country, Gingrich called Romney "Obama-lite," the Los Angeles Times reported.
"I think we want a candidate who works, pays taxes and believes in the Declaration of Independence, not someone who is clearly against the American ideals," the former U.S. House speaker said.
Gingrich stepped up his criticism of Romney for a comment the former Massachusetts governor made this week, when he told CNN he was not concerned about "the very poor" -- a comment Romney walked back after heavy criticism, saying he had misspoken.
"If you're a genuine conservative, first of all, you don't say that you don't care about the poor," Gingrich said Friday. "If you're a genuine conservative, you believe we are endowed by our creator with certain unalienable rights among which are life, liberty and the pursuit of happiness, and we think it is the left which has abandoned and betrayed the poor because its safety net is actually a spider web and it traps people into dependency."
"Obama's big food stamp, he's [Romney's] little food stamp, but they both think food stamps are OK," Gingrich continued. "I don't think food stamps are the future for America -- they're a necessary bridge."
Ryan Williams, a spokesman for the Romney campaign, said Gingrich was "borrowing Barack Obama's liberal talking points and is using them to attack Mitt Romney's career in the private sector."
"Like President Obama, Speaker Gingrich has spent his entire career in government and he has absolutely no idea how the private sector works," Williams said. "This is who Newt Gingrich is: an unreliable leader who undermines conservatives, hurts our party, and emboldens President Obama and his liberal allies."