LUTZ, Fla. -- Newt Gingrich stepped out of church Sunday morning and launched some of his most vitriolic attacks on Mitt Romney to date in the Republican primary, seeking to recover lost ground in the polls two days before primary voting ends here on Tuesday.

"I believe the Republican Party will not nominate a pro-abortion, pro gun-control, pro-tax increase moderate from Massachusetts," the former House speaker said.

Gingrich repeated the phrase "pro-abortion, pro gun-control, pro-tax increase" again during a 10-minute gaggle with reporters. He also began Sunday to wrap Romney's ties to Wall Street into his attacks on the former Massachusetts governor.

"They will not nominate somebody who raises millions from Wall Street to run ads that are false," Gingrich said.

"I have had a long record as a very hard-hitting Reagan conservative, and the idea that that record would be deliberately falsified by a Massachusetts moderate using money from Wall Street, from the very companies who have been getting money from the federal government, is really about as big an outrage as I've had in my career," he continued.

Gingrich spoke after attending services at Exciting Idlewild Baptist Church, a congregation of several thousand that meets in a vast 5,000-person auditorium. He complained earlier in the morning of a "carpet-bombing" on the TV airwaves by Romney's campaign and by outside groups supporting Romney, which have outspent Gingrich and outside groups backing him by a vast margin.

But Gingrich's comments to the press were a verbal bombardment against Romney. By tagging Romney as "pro-abortion, pro gun-control, pro-tax increase," he mischaracterized Romney's current positions on those issues. But the intent was clearly to bring attention to Romney's past positions on those things, which have been different, and to label him a flip-flopper -- in the most explosive and provocative terms possible.

And Gingrich, despite trailing decisively now in Florida polls, repeated and amplified his pledge from Saturday that he plans to run his campaign all the way to the Republican convention in August.

"I think Romney's got a very real challenge in trying to get a majority at the convention," Gingrich said. "I think this is going to be a straight-out contest for the next four or five months."

It is a deliberate move by Gingrich to get ahead of what he likely sees coming: a bad loss here in Florida, where the Romney campaign is already looking ahead to contests in February, publicly as well as internally and operationally. Gingrich knows that if he loses the Sunshine State, there will be much talk of when he will drop out, especially since February is likely to be such a brutal month for him.

Pushing back against the idea that he is finished in the race is key to Gingrich's ability to keep raising money, and to ensuring that big donors such as Las Vegas casino magnate Sheldon Adelson do not see donations to a pro-Gingrich super PAC as a bad investment.

Gingrich is also making a clear play now for the Tea Party vote. He cast himself as the representative of "the grassroots Republicans " and claimed former Alaska Gov. Sarah Palin as an ally, noting that she has been outspoken on his behalf this week. Gingrich also said that former New York City Mayor Rudy Giuliani is an ally of his.

"This is a campaign about the future of America and the future of the Republican party. Do you want an insider who's part of the system, who's been accepting huge amounts of taxpayer money to prop up giant institutions?" Gingrich said, making another reference to Wall Street. "Or do you want someone who's prepared to challenge that system head on and insist on very dramatic change in Washington?"

"I think that debate will go all the way to the convention," Gingrich said.