Republicans have balked at extending the program, noting that unemployment has fallen steadily in the past year, and arguing that weekly unemployment checks are a poor economic stimulus.

Democrats quickly rebutted Sen. Rand Paul, R-Ky., during the day for saying in a weekend television interview that an extension of the federal program would be "a disservice to these workers."

Appearing on Fox News Sunday, Paul said, "When you allow people to be on unemployment insurance for 99 weeks, you're causing them to become part of this perpetual unemployed group in our — in our economy."

But Rep. Sander Levin, D-Mich., said, "A disservice is essentially cutting them off on Dec. 28. They are looking for a job. They were laid off through no fault of their own. What do you do? Just give them the cold shoulder on Dec. 28? That's a disservice to humanity in my judgment," he said on MSNBC.

Additionally, Congressional Research Service statistics put the maximum duration for benefits at 73 weeks, not the 99 that was the case a year ago.

Democrats undermined their own political case for an extension last week when the party's leader, Rep. Nancy Pelosi of California, backed off an initial threat to oppose any budget deal that didn't provide for one.

At the White House,  spokesman Jay Carney said at the same time that President Barack Obama wants lawmakers to extend the program, but added, "The vehicle that they use to do that is less important than the fact that they do it."

Even a relatively modest budget agreement is far from a certainty, with one prominent tea party-aligned organization announcing it will likely oppose any deal to emerge from secretive negotiations.

"Heritage Action cannot support a budget deal that would increase spending in the near-term for promises of woefully inadequate long-term reductions," said the group, which was influential earlier this fall with tea party-backed lawmakers who pushed Republicans in the direction of a  partial government shutdown.

Any budget agreement is expected to have only a marginal impact on federal deficits, and instead is designed to ease the impact of across-the-board spending cuts over two years

The negotiators, Sen. Patty Murray, D-Wash., and Rep. Paul Ryan, R-Wis., have been discussing proposals to raise spending across a range of programs by between $60 billion and $70 billion. To offset the cost, they are considering reducing spending or raising fees elsewhere in the budget.

Among the items under consideration is an increase in the federal airline security fee that each passenger pays. Numerous officials have said Ryan and Murray also are discussing a proposal for federal workers to pay more of their own retirement costs, an item that was contained in rival budgets proposed by Obama and passed by the Republican-controlled House earlier this year.

Other possible elements of a year-end deal are short-term provisions to prevent a spike in milk prices and avoid the threat of a deep drop in the fees paid to doctors who treat Medicare patients.