ABC News' Michael Falcone and Devin Dwyer report:

Less than 24-hours after Tuesday night's debate, a top adviser to Mitt Romney's campaign switched his statement about whether the Republican presidential candidate would have supported the Lilly Ledbetter Fair Pay Act before it was passed by Congress and signed into law by President Obama in 2009.

Speaking to reporters after the debate at Hofstra University in New York, Romney aide Ed Gillespie said that Romney "was opposed to" the proposed legislation "at the time," but that he would not repeal it if elected.

Those comments were first reported by the Huffington Post's Sam Stein, and up until last night, neither the GOP presidential hopeful nor his campaign had disclosed whether Romney would have backed the fair pay law, which grants alleged victims more time to file suit in pay discrimination cases.

But it appears Gillespie got ahead of the candidate. In a follow-up statement sent to the Huffington Post Wednesday afternoon, he acknowledged that he misstated Romney's position.

"I was wrong when I said last night Governor Romney opposed the Lily Ledbetter act," according to the statement from Gillespie. "He never weighed in on it. As President, he would not seek to repeal it."

Indeed, in an interview this April, ABC's Diane Sawyer, asked Romney: "If you were president - you had been president - would you have signed the Lilly Ledbetter Law?"

"It's certainly a piece of legislation I have no intend- intention of changing. I wasn't there three years ago," Romney told Sawyer. "I'm not going to go back and look at all the prior laws and say had I been there which ones would I have supported and signed, but I certainly support equal pay for women and - and have no intention of changing that law, don't think there's a reason to."

Had Romney opposed the law, he would have been well within the mainstream of the Republican Party. The Ledbetter Act passed the House of Representatives in a mostly party-line vote, and Romney's own running mate, Rep. Paul Ryan, R-Wisc., voted against it.

In an interview Wednesday morning on CBS News, Ryan shed little light on Romney's original position, but he explained his own.

"Lilly Ledbetter was not an equal pay law. It was about opening up the lawsuits and statute of limitations," Ryan said. "It wasn't an equal pay law, and of course, we support equal pay."

Romney did not clarify his original position on the bill at Tuesday night's presidential debate, and his adviser's attempt to walk back his statement to reporters indicates the Romney campaign is trying to keep it that way.

But the Obama campaign has other plans.

Campaigning in Athens, Ohio on Wednesday evening, the president brought up the Romney campaign's changing statements on the Ledbetter Act, saying, "Just today his campaign admitted, well, he's never weighed in on that. What's so hard about weighing in on that? Either you believe in equal pay, or you don't."

Obama added, "I weighed in on it because it's the first bill I signed."

(Notably, equal pay for women has not improved significantly during President Obama's first term, but the Lilly Ledbetter Act has helped some victims of discrimination pursue their compensation claims in the courts, women's rights advocates say.)