Mitt Romney Income Tax Records Challenged By Rick Perry (VIDEO)

Rick Perry on Monday joined Rick Santorum and Newt Gingrich in calling for Mitt Romney to release his tax returns quickly, so that voters can find out now if they have a "flawed candidate or not."

"We need for you to release your income tax," Perry said at a GOP debate in Myrtle Beach, S.C. "We cannot fire our nominee in September. We need to know now."

Romney, given a chance to respond, at first didn't address the issue. When pressed later, however, he moved a step closer, saying he would "probably" do it around April if he becomes the nominee.

"I looked at what has been done in campaigns in the past with Sen. McCain and President George W. Bush and others," he said. "They have tended to release tax records in April or tax season. I hadn't planned on releasing tax records, because the law requires us to release all of our assets -- all of the things we own -- that I've already released. It's a pretty full disclosure."

"But you know, if that's been the tradition, I'm not opposed to doing that," he added. "Time will tell. But I anticipate that most likely I am going to get asked to do that around the April time period and I'll keep that open."

When asked again whether he was agreeing to release them, Romney replied, "I think I've heard enough from folks saying, 'Look, let's see your tax records.' I have nothing in them that suggests there's any problem, and I'm happy to do so. I sort of feel like we are showing a lot of exposure at this point. And if I become our nominee, and what's happened in history is people have released them in about April of the coming year and that's probably what I would do."

Romney earns much of his income from capital gains, which are taxed at a lower rate than that for even the lowest military service member. He has so far refused to release his taxes.