02/26/2012 11:13 am ET

Ron Paul: Rick Santorum Is 'Desperate'

Republican presidential hopeful Ron Paul slammed rival Rick Santorum as "desperate" after the former Pennsylvania senator openly speculated Paul and Romney had teamed up against him.

"I don't know what all that meant," Paul told CBS News.

While campaigning ahead of Tuesday's Michigan and Arizona primaries, Santorum expressed his annoyance with Paul for his lack of attacks on Romney. Paul has said that the reason he's holding back from hitting Romney is so he can earn the votes of "the anti-Romney" candidate's supporters.

"Right now the anti-Romney candidate is Santorum, so I have to get his votes, as I did at one time with Gingrich," Paul said.

Paul's not the only one holding back attacks. During his much-hyped address at Ford Field in Detroit on Friday, Romney carefully avoided insulting Paul.

Romney supporter and former Minnesota governor Tim Pawlenty has defended the two GOP hopefuls, saying he doesn't think Romney and Paul have cut a "back room deal."