Updated at 9:05a.m. ET:

WATERLOO, Iowa -- On the first day of the New Year, Newt Gingrich admitted to having been “Romney-boated” with the immense amount of negative ads being run against him, vowing that his campaign will run more contrast ads going forward.

Mitt Romney “didn't get rid of me, he just slowed me down,” Gingrich told reporters in Marshalltown, Iowa, Sunday afternoon. Asked whether he felt like he had been “swift-boated” by the barrage of ads run against him in recent weeks, Gingrich responded, “I feel Romney-boated” – a reference to the outside advertising campaign launched against Democratic nominee John Kerry in 2004.

The former House Speaker even hinted that Romney was trying to buy the election.

“He would buy an election if he could,” Gingrich told NBC News. But he wouldn’t directly say Romney was attempting to buy the 2012 election. “Well I dunno, $3.5 million in negative ads, you tell me,” Gingrich continued. 

Romney, campaigning on the opposite side of the Hawkeye State Sunday, pushed back against these allegations from the Speaker. 

“Speaker Gingrich I think announced that he raised $10 million this quarter and he ought to be proud of that. We’re working hard to raise funds, as well, this is an election,” Romney said in Atlantic, Iowa. “However, that’s not being driven by money raised, its being driven by message connection with the voters, debate and um experience and I think that those are the features that are driving the campaign so far and I think they probably will be through the entire process.”

Gingrich told reporters his campaign would be increasing the number of positive yet contrast ads on television and radio moving ahead to better combat the negative attacks from his GOP rivals.

“If somebody spends $3.5 million lying about you, you have some obligation to come back and set the record straight,” the Speaker said after his campaign heavily underestimated the damage these ads could do.

The negative attacks have worked here in the first-in-the-nation caucus state: Gingrich dropped from first place in the Des Moines Register’s early December poll to fourth place in Saturday’s DMR poll. Romney now leads in Iowa, according to the new poll, with Ron Paul and Rick Santorum finishing ahead of Gingrich. 

Gingrich told the standing-room only crowd inside LJs Neighborhood Bar and Grill here in Waterloo that not answering these negative ads was his biggest weakness. 

“I am too reasonable and I should have responded to the negative ads two weeks earlier,” Gingrich said after an interesting exchange between himself and wife, Callista, when the Speaker was asked about his biggest weakness.

The crowd began to laugh after Gingrich and Callista looked at one another with smiles about Newt’s biggest weakness. “Go ahead,” Callista told him as many in the audience expected him to perhaps mention his infidelities years ago. Rather, Gingrich stayed the course and linked his weakness answer back to the negative ads.

The Speaker’s ‘Jobs and Growth Bus Tour’ continues Monday with four stops in Eastern Iowa on caucus eve.

NBC’s Garrett Haake contributed to this report.