Newt Gingrich says Mitt Romney should release his tax returns before primary voters head to the polls in South Carolina on Saturday.

“It’s interesting that Romney agreed that he ought to release his income taxes but he doesn’t want to do it until April,” Gingrich said Tuesday on CBS. “I think the people of South Carolina ought to know now — if there’s nothing there, why hide it until April, and if there’s something there, don’t the people of South Carolina deserve to know before Saturday?”

Romney has said that his campaign has complied with everything that’s required of it, and that if need be he’ll release his personal income taxes next year.


However, his rivals contend that all of the candidates should be properly vetted in advance to avoid a general-election surprise that benefits President Obama.

Gingrich said he will release his taxes this week, and at Monday’s debate, Rick Perry directly confronted Romney on the matter.

“Mitt, we need you to release your income tax returns so the people of this country can see how you made your money,” he said. "We cannot fire our nominee in September. We need to know now."

Romney avoided answering Perry at the time, but pressed later by moderators, he said he would probably release his returns in April after filing for 2011.

“I think last night, frankly, weakened [Romney] a little,” Gingrich said. “If you’re a South Carolinian you’re saying, ‘Wait a second, why don’t you want me to know about it, why are you going to wait until after I’ve voted?’ Last night he conceded in principle that he owes it to the public to share. It strikes me that he ought to do it before South Carolina votes.”

While none of the candidates has said he thinks there is a problem with Romney’s taxes, the returns likely show that the former Massachusetts governor accumulated great personal wealth while an executive at Bain Capital.

Romney’s time at Bain has been a target during the Republican primary, as Perry and Gingrich have gone after him for being a “vulture” capitalist, claiming he made money by laying off workers and picking companies clean.

The Republican establishment has defended Romney against this argument, saying it is anti-capitalist and gives ammunition to the Obama campaign.

But Gingrich defended it as normal vetting that needs to happen before “the Obama machine” focuses on it.

“I don’t understand this attitude of protecting a candidate from telling the truth,” Gingrich said. “We want people to be able to withstand the attack of the Obama machine this fall. We better understand before the nomination whether or not our candidates are capable of withstanding that kind of attack. The worst thing for us to do would be to nominate somebody and then have them disintegrate in September because Obama found some weakness and went after it relentlessly.”