MILWAUKEE (MCT) - Echoing criticism made by Republican John McCain, Hillary Rodham Clinton on Sunday accused rival Democrat Barack Obama of backing off a pledge to use public funds in the fall election and said it raised credibility issues with the Illinois senator.

"My understanding is that Senator Obama said he would (take public financing) and that now he's saying he won't," Clinton said in an interview with the Milwaukee Journal Sentinel.

Accepting public funds for the fall general election comes with spending limits. That means surrendering a major financial advantage in the case of a campaign, like Obama's, that has shown a capacity to raise far more money privately than its opponents.

"Actions speak louder than words. No matter how beautiful the words are and how well presented, you've got to get beyond the words. And now we're seeing how the words don't even mean what we thought they meant," Clinton said. "So I think it raises some serious questions about what it is he stands for."

Both McCain and Clinton are charging that Obama is backtracking from a promise to accept public financing in the general election in the event his GOP opponent does the same.

They are basing that on a 2007 questionnaire Obama filled out from the Midwest Democracy Network, which asked whether he'd forego private funds and accept public money - along with the spending limits that go with it - provided the other party's nominee also made that commitment.

Obama answered: "Yes. … If I am the Democratic nominee, I will aggressively pursue an agreement with the Republican nominee to preserve a publicly financed general election."

Obama's campaign says its commitment is to sit down with the GOP nominee and "talk this through," Obama strategist David Axelrod said Sunday on CBS' "Face the Nation."

"We're not backing away," Axelrod said.

At a news conference Friday in Milwaukee, Obama said: "I think it would be presumptuous of me to start saying now that I'm locking myself into something when I don't even know if the other side is going to agree to it, and I'm not the nominee yet."

If he wins the nomination, Obama said, "I assure you that my folks and John McCain's folks will sit down and see if we can arrive at a common set of ground rules."

McCain says he will commit to taking public funds if the Democratic nominee does so.

Clinton has not made a commitment about taking public funds for the fall if she were to be the nominee.

"If I'm the nominee, I will look at it," Clinton said in the Sunday interview, but, she said, unlike Obama, "I have made no promises."

Clinton said the controversy "is more about (Obama's) credibility than about the issue" itself.

In an interview Friday, Democratic Sen. Russ Feingold of Wisconsin, a vocal advocate of public financing, spoke about the issue.

"I would hope that all these candidates would do everything they can to respect the public financing system," Feingold said. "We don't want this election to be where people say this was won because one candidate had more money than the other."

(c) 2008, Milwaukee Journal Sentinel. Distributed by McClatchy-Tribune Information Services.