Responding to calls by Mitt Romney that he release the details of his work with Freddie Mac, former House speaker Newt Gingrich (R-Ga.) will release via e-mail his contract with the mortgage lender, according to a spokeswoman for the Gingrich Group.

Former House speaker Newt Gingrich (R-Ga.). (Matthew Cavanaugh/Getty Images)

Romney spent Monday attacking Gingrich over his work with Freddie Mac, which paid Gingrich $1.6 million, accusing him of being a lobbyist and saying that his work with the lender could be an “October surprise.”

Gingrich denies being a lobbyist. “I was not a lobbyist, I was never a lobbyist, I never did any lobbying. Don’t try to mix these things up. That fact is I was an adviser strategically,” he said Sunday on “Meet the Press.”