Republican presidential candidate Mitt Romney pledged on Sunday to release his tax returns this week, bowing to pressure from critics and hoping to make up for a misstep that helped rival Newt Gingrich win South Carolina's primary race.
Long considered the frontrunner, Romney stumbled badly in debates last week on his delay in disclosing his tax returns and then lost his air of being the inevitable Republican nominee after a resurrected Gingrich soundly defeated him in the third contest.
Gingrich, the former speaker of the House of Representatives, pounced on Romney's surprising weakness and rode it to victory on Saturday, trouncing the former governor of Massachusetts by 40 percent to 28 percent in South Carolina.
Trying to regain his momentum as the race heads to the pivotal state of Florida, Romney sought to draw a line under the bad week and fix his error. He said he would release his 2010 returns and an estimate for 2011 on Tuesday. "We made a mistake holding off as long as we did and it just was a distraction," Romney said on Fox News Sunday.
Last week, Romney said he pays a tax rate of around 15 percent, a low rate compared to many American wage earners but in line with what wealthy individuals pay on income that largely comes from investments.
One of the wealthiest US presidential candidates in history, Romney emphasised he was releasing two years of returns after Gingrich posted his taxes for one year - 2010 - on Thursday.
Both candidates are gearing up for a tough fight on January 31 in Florida, one of the most important states in the contest to determine who will take on Democratic President Barack Obama in the November 6 election.
Gingrich, who has see-sawed in national polls and must prove to Republicans that he is the most "electable" candidate despite political and personal baggage, praised Romney and said the issue would be moot once the taxes were out.
"I think that's a very good thing he's doing and I commend him for it," Gingrich said on NBC's "Meet the Press."
"And as far as I'm concerned, that particular issue is now set aside and we can go on and talk about other bigger and more important things."
But the tax issue will almost certainly not go away.
Income inequality has become a leading topic in the presidential race, and Obama has signalled he will talk about an economy that works "for everyone, not just a wealthy few" in his State of the Union address on Tuesday night.