HIALEAH, Florida--Republican Newt Gingrich struggled to halt surging rival Mitt Romney's momentum on Sunday, accusing him of launching false attacks as polls showed Romney widening his lead two days before Florida's presidential primary.

Romney, who has battered Gingrich in a flood of television ads and two debates in Florida last week, opened a double-digit lead over the former U.S. House of Representatives speaker in four polls released on Sunday.

Gingrich said the race was closer in Florida than the polls indicated and vowed to fight on beyond Tuesday's vote. Conservatives eventually would rally behind his candidacy and block Romney's nomination, he said.

"I believe the Republican Party will not nominate a pro-abortion, pro-gun control, pro-tax increase moderate from Massachusetts," Gingrich said after attending a Baptist church in Lutz, Florida.

"They will not nominate somebody who raises millions from Wall Street to run ads that are false," he said. "So this is going to be a straight out contest for the next four or five months."

Earlier, Gingrich accused Romney of distorting his record. "He has a basic policy of carpet-bombing his opponent," he said on "Fox News Sunday". "I give Governor Romney's campaign due respect for the sheer volume of negativity that they use and the sheer amount of money they raise on Wall Street."

Romney told supporters in Naples, Florida, that Gingrich was making excuses and should take a look in the mirror. "My own view is that the reason Speaker Gingrich has been having a hard time in Florida is the people of Florida have watched the debates and listened to the speaker, have listened to the other candidates, and have said, 'You know what? Mitt Romney's the guy we're gonna support'," he said.

Romney this week attacked Gingrich for his ties to the mortgage agency Freddie Mac and the collapse of the housing market--an open wound in Florida, where residential property values have plunged about 45 percent from early 2006.

Gingrich picked up the endorsement on Saturday night of former rival Herman Cain, who dropped out of the Republican race in December after allegations of sexual harassment and an extramarital affair. But polls have shown the race moving toward Romney in Florida for days, reversing the momentum that Gingrich built after scoring an upset of Romney in South Carolina on Jan. 21.

A Reuters/Ipsos poll on Sunday showed Romney, the former Massachusetts governor, holding a 12 percentage point advantage over Gingrich in Florida. Three other polls on Sunday put Romney's lead in Florida at between 11 and 15 points.

"It's clear that Romney has run a much more focused and effective campaign in Florida than Newt," Republican strategist Matt Mackowiak said. "Newt is playing defense every single day in every way."

The large and complex Florida electorate, with 10 media markets and a sizeable blocs of Hispanic, Jewish and elderly voters, is seen as a crucial test for candidates. Romney campaigned in Hialeah, a heavily Hispanic suburb of Miami, on Sunday afternoon. At a popular Cuban restaurant he carved a roast suckling pig, typically served on celebratory occasions, as he tried to woo Hispanic voters.

"My father doesn't speak Spanish," son Craig Romney told the crowd in Spanish. "But he does speak the language of the economy."

A Miami Herald survey showed 52 percent of Hispanic voters favor Romney, compared to 28 percent who support Gingrich. "Mitt Romney has shored up support among his key backers while cutting his losses among Tea Party voters," Marist College pollster Lee Miringoff said. "The net effect is that he is in the driver's seat as Tuesday's primary approaches."

Gingrich acknowledged he faced an "uphill" battle to overtake Romney in Florida, but disputed the size of Romney's lead. "I think it will be much, much closer than these polls. We have a shot at winning," Gingrich said on Fox. "But frankly it's uphill against the sheer weight of Romney's money and the negativity of his campaign."

A win in Florida would be a vital boost for Romney, who was backed in the last week by several prominent conservatives worried a Gingrich nomination would harm Republicans in the Nov. 6 election against President Barack Obama.

Gingrich said he was happy to ruffle feathers in the party establishment and he was not bothered by criticism from party elders like former Senate Republican leader Robert Dole. "I am not running for president to manage the decay of the United States to the satisfaction of the establishment," he said at an afternoon rally at The Villages, Florida, a retirement community where about 1,000 people gathered to hear him.

If his candidacy makes the "old order uncomfortable, my answer is: Good," he said.

Romney's camp mocked Gingrich's claim that he is outside the party establishment, given his years in Congress and post-congressional career in Washington power circles. Eric Fehrnstorm, a senior Romney aide, said on Twitter: "Things that make me laugh: circus clowns, Charlie Chaplin movies and the idea that Newt Gingrich is an 'outsider'."