Updated

A former campaign adviser to President Obama is facing fierce opposition from at least one Senate Republican to her nomination as deputy director of the White House Office of Management and Budget.

Sen. Jeff Sessions, the top Republican on the Budget Committee, says that Heather Higginbottom, a former legislative director for Sen. John Kerry, doesn’t have the chops to become the deputy in charge of the government’s $3.7 trillion budget.

"Ms. Higginbottom's experience level is stunningly lacking," Sessions said Thursday. "She's never served on the Budget Committee, never studied business. Never run a business. Never been a mayor of a town."

"The most important thing is she does not have the kind of experience in business or accounting or budget or responsibility or management that you would look for in the second-in-command of the Congressional Budget Office, the most central unit in our entire governmental structure, committed to containing wasteful spending," he said. "We need somebody who will go after waste, fraud and abuse."

The fate of her nomination is uncertain after the Senate Budget Committee delayed her confirmation vote Thursday and rescheduled it for Tuesday. If her nomination clears the committee, the remaining hurdle will be a vote in the full Senate.

Her confirmation hearing comes as House Republicans and Senate Democrats wrangle over what and how much to cut from the federal budget. House Republicans passed a bill in February slashing $61 billion. Senate Democrats are willing to cut as much as $33 billion. But Tea Party-backed conservatives, who want $100 billion cut, are pressuring Republican leaders not to compromise.

With the economy still recovering from a steep downturn, Sessions says the country cannot afford an inexperienced candidate for a key budget post.

"It is going to be very hard for the president to publicly defend this nomination," Sessions spokesman Stephen Miller told FoxNews.com. "As Sen. Sessions has said, it's like appointing a general in the middle of a war who has no military experience."

But OMB hasn't shied away from defending Higginbottom's record.

"Heather has worked at the highest levels of policymaking in the legislative and executive branches for more than a decade," OMB spokesman Kenneth Baer said in an email to FoxNews.com. Higginbottom was tapped by OMB Director Jack Lew, who was once deputy director, and President Obama "because they have seen firsthand Heather's command of the issues and depth of her experience," Baer said.

"We expect Heather to be confirmed swiftly so that she can get to work on the tough fiscal challenges facing the country," he said.

Higginbottom earned Sessions' ire when she defended claims by Obama and budget director Jack Lew that the president's budget will allow the government to "live within our means," "spend money that we have each year," and "begin paying down our debt."

Obama's 2012 budget projects that the deficits will total $7.21 trillion over the next decade while the nonpartisan Congressional Budget Office estimated an even higher deficit of $9.5 trillion. The White House is aiming to balance the budget except for interest payments on the $14 trillion national debt, which is known as "primary balance." That occurs when the deficit is about 3 percent of the size of the economy, and economists say deficits of that magnitude are generally sustainable.

But CBO predicted that the deficit never gets below 4 percent of the gross domestic product, which means that by 2021, the portion of the debt held by investors and foreign countries will reach a dangerously high 87 percent.

Under intense questioning from Sessions during her nomination hearing, Higgonbottom said the president's budget stabilizes the annual deficit. But she dodged Sessions' question about whether deficits increase in the final three years of the president's budget.

Republicans have also seized on Higginbottom's testimony before the Senate homeland security committee in which she cited her experience in policymaking as a qualification for the job.

When Sen. Scott Brown, R-Mass., asked her whether she has any accounting or budgetary experience aside from policymaking, Higgonbottom said, "I'm not accountant. But the president's budget is an articulation of his policy agenda."

While Sessions says she is the least qualified nominee for this post in decades, other deputy budget directors have also lacked relevant experience for the job.

Joel Kaplan, a deputy budget director in the Bush administration, previously served as a special assistant to the president, focusing on nonbudgetary issues, and as a policy adviser to President Bush's campaign.

And Nancy Dorn, who also served as deputy budget director in the Bush administration, previously worked in legislative affairs for Vice President Cheney and was a foreign policy adviser to former House Speaker Dennis Hastert.