Republican president hopeful Ron Paul has intensified his assault on Newt Gingrich, with new critiques on his personality.

U.S. congressman Ron Paul, in an interview with Fox News channel, said Gingrich - a former House speaker - lacked the moral right to speak in support of war, particularly when he had a history of deferments to escape military service.

Paul, who is a veteran Air Force officer, is critical of U.S war policy, while Gingrich is an aggressive supporter of the country's armed conflicts across the world. Paul further noted he found his rival's war policies annoying.

When he himself was not ready for military service, how can he speak about sending our kids to war zone? asked Paul, emphasizing Gingrich's unsuitability to comment on military policy.

Paul is referring to Gingrich having sought and received several deferments, citing his student and early marital status; his first marriage was when he was 19.

Meanwhile, Paul has released a series of hard-hitting advertisements, showing Gingrich as corrupt and indecisive on policy issues. In response, Gingrich labeled the ads as informative. His rival defended his strategy by saying the American people had a right to know all they could about future Presidents of the nation and that the allegations and incidents brought into the public sphere, through his ads, reflected Gingrich's personality.