Even as Republicans and Democrats fight over how to avoid looming tax hikes and budget cuts, Congress is weighing another crucial and potentially contentious financial matter: whether to increase the nation's sky-high borrowing limit, perhaps permanently.

President Obama proposed during negotiations over the so-called fiscal cliff that he be given permanent authority to raise the debt ceiling -- the amount the government can borrow to keep operating -- without the approval of Congress.

The White House said it's necessary to avoid another near-shutdown of the government when the current limit, $16.4 trillion, is reached early next year.

Congress used to approve increases in the borrowing limit routinely. But as the federal budget deficit grows and the country sinks further into red ink, Republicans have started using the debt-ceiling debate as a means of forcing the president to accept deep spending cuts that match any increase in borrowing.

The last time the two sides clashed over the borrowing limit was August 2011, when the fight grew so fierce -- and the government came so close to defaulting on its obligations -- that bond-rating agencies lowered the U.S. government's rating for the first time ever. That cost taxpayers an extra $1.3 billion in borrowing costs.

"Nobody likes that vote," said Rep. Mike Simpson, R-Idaho. "That is the burden of the majority, that they have to vote on that, and it makes it pretty difficult."

Obama and Democrats said giving the president the power to raise the debt ceiling without congressional approval would provide economic stability and ensure the government would continue to pay its bills.

"We just cannot have the debt-limit extension held hostage to something else," said Sen. Tom Harkin, D-Iowa. "I think it's time we put this behind us."

But lawmakers are resisting the proposal, noting that it would strip Congress of its authority over federal spending.

Outgoing Rep. Steven LaTourette, R-Ohio, said the debt ceiling fight has evolved from a noncontroversial vote "into something that has got a life of its own." But he still believes Congress should retain the power to reject an increase.

Under Obama's plan, lawmakers could block an increase only if they muster a supermajority, which requires two-thirds majority of each chamber.

"He's the last person who should have limitless borrowing power," said Senate Minority Leader Mitch McConnell, R-Ky., citing the escalating spending during Obama's first term. The debt ceiling debate, he said, has become "the only way we ever cut spending around here."

Democrats said Obama's plan is rooted in a proposal first offered by McConnell, who during the August 2011 debt ceiling debate suggested the president be allowed to override Congress if it refused to raise the debt limit.

"It's something that was proposed by the Republican leader of the Senate," said Nadeam Elshami, a spokesman for House Minority Leader Nancy Pelosi, D-Calif.

Republicans dispute the White House claim, saying McConnell proposed granting the president additional authority only temporarily and only if Obama agreed to $2 trillion in spending cuts.

Moreover, many Republicans opposed giving the president the additional authority even when McConnell proposed it.

"The idea that we would ever let one person decide the amount of debt we are going to assume?" a McConnell aide said. "There's no way you can sell that here."