WASHINGTON - Taking the vanguard of a Republican revolt against President Obama and their own GOP leaders, Rep. Michele Bachmann and two other Tea Party members said Wednesday there is no need to raise the federal debt limit in order to continue paying Social Security benefits.

"This is a misnomer that the president and the Treasury secretary have been trying to pass off on the American people," said Bachmann, R- Minn., a presidential candidate who is leading the polls in her native Iowa.

Bachmann joined with Rep. Steve King, R-Iowa, a close ally, to introduce a bill that they said would sidestep default by limiting government payments primarily to holders of U.S. debt and members of the military. King acknowledged that the plan would leave room for only 58 percent of federal obligations, forcing cuts of about $1 trillion a year. Social Security, Medicare, defense and interest on the national debt alone make up 56 percent of the U.S. budget, so the bill would essentially force the government to abandon almost all other functions.

Bachmann vs. GOP leaders

The Bachmann-led move pointed to the growing fissure within the Republican Party between its leaders -- who spent Wednesday repeating the potential for catastrophe in not raising the federal debt limit -- and many members of Congress who seem set on testing what will happen if the government cannot borrow additional money. That rift has made it look increasingly unlikely that a debt agreement can pass the Republican-controlled House in time to avert the first default in U.S. history early next month.

Senate Minority Leader Mitch McConnell, in a radio interview, predicted that if Congress fails to act, Obama will argue "that Republicans are making the economy worse and try to convince the public -- maybe with some merit -- if people start not getting their Social Security checks."

He further warned that a default could spell disaster for the Republican Party's future.

House Speaker John Boehner, the Ohio Republican who has been locked in debt talks with the White House, agreed that the default that could come as soon as Aug. 2 poses real dangers for the economy. "Nobody wants to go there because nobody knows what's going to happen. It's a crapshoot," he said.

Separately, Federal Reserve Chairman Ben Bernanke warned lawmakers that failure to raise the nation's borrowing limit could send "shock waves through the entire financial system." He said that it was a "matter of arithmetic'' that Social Security, Medicare and Medicaid payments would all be cut at some point after a default.

But Bachmann, King and Rep. Louie Gohmert of Texas shrugged off those predictions.

"As far as what might happen in the global financial markets, no one knows," King said on Capitol Hill. "I've yet to find anybody who can lay that all out for me in a convincing fashion."

Though considered a long shot, the legislation highlights the rift between Bachmann's Tea Party faction and GOP congressional leaders who are negotiating with the White House on ways to fill the budget gap. McConnell sought earlier this week to give the president new authority to raise the current $14.3 trillion debt limit without GOP support.

King called McConnell's proposal "the fox in the hen house."

'We don't believe that'

Bachmann's new plan echoes one advanced by former Minnesota Gov. Tim Pawlenty, a rival for the 2012 GOP presidential nomination. Pawlenty has argued against what he calls the "false choice between more debt and default."

Pawlenty spokesman Alex Conant said the former two-term governor had not seen the Bachmann bill, "but he's been leading on this idea generally."

Pawlenty wrote an opinion piece in January proposing that instead of raising the debt ceiling the government instead "sequence" federal spending to first pay interest and principal on the debt, along with other priorities like the military.

Bachmann and her Tea Party allies, who have come together before to push for a balanced budget amendment and the attempted repeal of Obama's health care overhaul, said their plan would uphold the nation's credit rating.

Democrats fired back that Bachmann's proposal would put the nation's foreign creditors ahead of seniors and others who rely on government health and pension benefits.

"Michele Bachmann would rather protect China than our seniors?" said Haley Morris of the Democratic Congressional Campaign Committee.

Bachmann rejected Obama's warning on Tuesday that Social Security benefits checks could be at risk starting Aug. 3 if a debt ceiling agreement is not reached. "We don't believe that for a moment," she said.

Gohmert publicly advised Boehner "not to believe the president anymore."

While Bachmann's bill calls for deep cuts in U.S. spending, it doesn't say where those cuts would fall. She and her allies were vague about the details, though the scope of the cuts would have to be extensive.

"It's going to require delaying some payments, paying others, moving things around, making judgments," King said. "Or you could go with cutting government services in totality, place after place by priority. I would suggest that the president find some combination of that ... It's not Armageddon."

Associated Press contributed to this report. Kevin Diaz is a correspondent in the Star Tribune Washington Bureau.