AP

After taking heat in Thursday GOP debate in South Carolina over not releasing his tax returns and following a thrashing by Newt Gingrich in the primary vote Saturday, Mitt Romney announced that he will release his 2010 tax returns on Tuesday.

"I'll do them on Tuesday of this week. I'm also at the same time going to release an estimate for 2011 tax returns. So you'll have two years, people can take a good look at it," Romney told Chris Wallace on Fox News Sunday.

"We made a mistake in holding off as long as we did," Romney said. "It was a distraction...we want to get back to the real issues of the campaign." The returns will be available on the Internet.

Romney had previously said he would release his tax returns in April if he became the nominee.

Rival Newt Gingrich, who released his 2010 tax return in the midst of the Thursday debate, commended Romney's reversal on NBC's Meet the Press. "I think that's a very good thing he's doing and I commend him for it," he said.

Romney told Wallace that he pays "substantial" taxes. When asked on Tuesday about his tax rate, Romney said, "What's the effective rate I've been paying? It's probably closer to the 15 percent rate than anything. Because my last 10 years, my income comes overwhelmingly from some investments made in the past, rather than ordinary income or rather than earned annual income. I got a little bit of income from my book, but I gave that all away. And then I get speakers fees from time to time, but not very much."*

In his disclosure to the Federal Election Commission, Romney indicated net worth was between $190 and $250 million.

Romney supporter New Jersey Gov. Chris Christie said the former Massachusetts governor should not be criticized for being extraordinarily successful in business. "Americans don't want a failure as president," Christie told David Gregory on Meet the Press Sunday.