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Republican presidential candidate Newt Gingrich speaks to supporters on Friday in Columbia, South Carolina.

DES MOINES, Iowa – It appears Newt Gingrich isn’t playing nice anymore.

The Gingrich campaign is out with its first opposition email directly hitting none other than GOP rival Mitt Romney -- a move that signals a departure from the positive-only campaign Gingrich himself promised to run.

“Can we trust a Massachusetts Moderate to enact a conservative agenda?," Gingrich Communications Director Joe DeSantis writes in the email sent out Monday evening. "Our campaign might have plenty of things to say about that, but the best response certainly comes from Mitt Romney himself: 'I think people recognize that I am not a partisan Republican. That I'm someone who is moderate, and that my views are progressive.'"

The email, labeled “FACT SHEET: MITT THE MASSACHUSETTS MODERATE,” makes fun of Romney’s new television ad running in Iowa during which the former Massachusetts Governor portrays himself as a "conservative businessman.” It quotes what people have said about Romney and a few things Romney has said in the past.

Ironically, the former House Speaker is currently running a TV ad in Iowa himself, during which he says: “Others seem to be more focused on attacks, rather than moving the country forward. That's up to them.”