More than any single issue, Newt Gingrich has been hammered in TV ads over the $1.8 million he and his companies earned as a consultant for failed mortgage company Freddie Mac. Now, Gingrich tells ABC News, he is preparing a TV ad to directly defend his actions.

"We have a great story" to tell about Freddie Mac "and will probably run an ad by the time we get to New Hampshire or South Carolina," Gingrich said.

What is the story? Gingrich said he can point to evidence that he opposed the 2008 bailout of Freddie Mac and never advocated for them on Capitol Hill. He also says only a fraction of the $1.8 million contract went to him personally - the bulk of it going to his companies.

Failing to respond to the Freddie Mac ads run by his opponents, Gingrich said, was a mistake that may cost him dearly in Iowa.

"I think I should have explained the Freddie Mac thing, because we have a great explanation," Gingrich said in an interview with ABC News in Independence, Iowa. "In fact, the New York TImes reported the only time I talked about it, I said don't vote to give them any money - and that was in July of 2008."

"And we had JC Watts who was the chair of the Freddie Mac watch committee who said in seven years I never once approached him," Gingrich said.