Londonderry, New Hampshire (CNN) – Newt Gingrich responded to a call Monday by GOP rival Mitt Romney to return the money he received from mortgage giant Freddie Mac by issuing his own challenge. "If Gov. Romney would like to give back all the money he's earned from bankrupting companies and laying off employees over his years at Bain that I would be glad to then listen to him," Gingrich told reporters after a town hall, referring to the company Romney ran. "And I'll bet you 10 dollars, not 10 thousand that he won't take the offer."