Mitt Romney has been attacked by his rivals for the Republican presidential nomination, who accused him of lacking authenticity and a sufficiently conservative record, and failing to dis-avow dishonest advertisements by his supporters.

In the second of back-to-back debates leading up to tomorrow’s crucial New Hampshire primary, Newt Gingrich, Rick Santorum and Jon Huntsman took a much more aggressive stance towards Mr Romney than they had the previous night, when they battled each other more than him. In one early exchange, Mr Gingrich accused Mr Romney of spouting “pious baloney” when the former Massachusetts governor claimed he had not aimed for a career in politics but instead his “l(fā)ife’s passion has been my family, my faith and my country”.

Mr Gingrich has been the most vocal critic of Mr Romney in recent days, lambasting him as a “timid moderate” who would have serious trouble unseating Barack Obama from the presidency in November. He and Mr Santorum, the former Pennsylvania senator who finished a close second in last week’s Iowa caucuses, appeared to team up in an attempt to shake Mr Romney’s confidence and stall his momentum. “If his record was so great as Massachusetts governor, why didn’t he run for re-election [in 2006],” said Mr Santorum, accusing Mr Romney of “bailing out” rather than fighting for his principles.