Newt Gingrich escalated the negative campaigning between himself and GOP rival Mitt Romney on Sunday, scrambling to blunt the Massachusetts governor’s momentum two days before the Florida primary.

Republican presidential hopeful Newt Gingrich (L) speaks to a supporter as he arrives at Idlewild Baptist Church in Florida on Sunday. (STAN HONDA/AFP/Getty Images)

“I don’t know how you debate a person with civility if they’re prepared to say things that are just plain factually false,” Gingrich said during an appearance on ABC’s “This Week.”

Gingrich, who won the endorsement of former candidate Herman Cain over the weekend, said “the conservatives are clearly rejecting Romney” and claimed the mantle as the race’s true conservative candidate.

Gingrich also renewed his complaints about the Romney campaign’s negative attacks on him, financed by what Gingrich called wealthy backers from Wall Street investment banks.

“He has a basic policy of carpet-bombing his opponents,” Gingrich said on ‘Fox News Sunday,” conceding that he might lose the Florida contest.

But, speaking on ABC’s “This Week,” he presented himself as the true conservative candidate in the GOP primary race, saying conservatives “are clearly rejecting Romney.” He pledged that the race would “go on all the way to the convention.”

“We’re seeing the conservative moment start to come together,” Gingrich said on Fox. “I think it’s going to be very close. We have tremendous effort under way to reach out to the conservatives.”

Texas Rep. Ron Paul has invested little in the Florida contest and campaigned over the weekend in Maine, which holds caucuses next Saturday. Speaking on CNN’s “State of the Union” Sunday, he vowed to stay in the race despite his focus on small caucus states.

“We’re going to stay in and see what comes of it,” Paul said, acknowledging that his campaign has less money than some of his rivals.

“It is a rough road competing with establishment money,” he said.