Budget negotiators are nearing a deal that could ease the way for leaders to avert another government shutdown before the 2014 elections, but only if rank and file — particularly in the House — buy into the agreement.

Senate Budget Chairwoman Patty Murray, D-Wash., and House Budget Chairman Paul D. Ryan, R-Wis., are expected to announce a framework in the coming days that would set a top-line number for appropriators higher than the current sequester levels but lower than what Democrats have previously demanded.

According to sources, the increased spending would be offset by less controversial pay-fors, including spectrum sales and some mandatory health care cuts. The two lawmakers have been meeting regularly, including a session Wednesday. Murray attended despite the Senate’s recess.

But many top leadership aides in the Capitol are skeptical that any agreement between Murray and Ryan can pass the House, and those aides feel largely in the dark about what might happen after the deal is struck, with or without successful votes on it in both chambers. Republican leaders have vowed they will not shut down the government again, but how Congress will keep it open remains up in the air.

Appropriators could move forward with the agreed-on top-line numbers without full congressional approval of the Murray-Ryan proposal and spend the four weeks between an announcement and the Jan. 15 government shutdown deadline to put together an ominbus spending package. But they would have to do so under the assumption that enough House Republicans would break from party hardliners and join House Democrats to pass the spending measure.

The other alternative would be to pass a full-year continuing resolution at current spending levels, an action GOP appropriators and Democrats want to avoid.  But such a move could be most reflective of political reality. Senate aides in both parties insist that if the House can pass a CR at current levels, Democrats will have no choice but to approve it, pinned between their previous support of the Budget Control Act and fear of being blamed for a shutdown.

Amid widespread pessimism about Congress’ ability to function normally, appropriators have remained optimistic about their ability to get spending bills done if an agreement is reached, even in the short time frame. Congress is tentatively scheduled for one work week before Christmas and another in January before its deadline.

“I don’t think there’s a need for a CR now,” House Appropriations Chairman Hal Rogers, R-Ky., said this week. “I believe we can do an omnibus bill that is done by [Jan.] 15.

“We’ve cleared out some underbrush,” Rogers said of some of the legwork that’s been done by his committee in concert with Senate Appropriations Chairwoman Barbara A. Mikulski, D-Md. “We’re ready to go.”

At a minimum, an agreement between Ryan and Murray would represent sign-off from most congressional leaders — though Senate Minority Leader Mitch McConnell has said that any spending level above the BCA mark would be unacceptable. Both Ryan and Murray are close with their respective leaders.

Senate Majority Leader Harry Reid, D-Nev., confirmed late Tuesday in an interview with Las Vegas NBC affiliate KSNV that Ryan and Murray were closing in on an agreement and reiterated his faith in his chairwoman.

“Patty Murray’s one of my favorite people,” Reid said. “She’s somebody who I have great admiration for. If anyone can get it done, she can, and I keep in touch with her. And it is close, but close only counts in horseshoes, and so I would hope — the government’s not going to close — and I would hope, I would hope that we can get rid of sequestration. We don’t need a meat ax. We need a scalpel.”

Though both Murray and Ryan have been praised for their efforts, it’s unclear how many House Republican votes Ryan could secure for an omnibus spending package at the higher spending level. Those who would support such a deal — such as appropriators and moderates — would have been there for Rogers and leaders no matter what. The GOP force behind the shutdown was not the establishment, but rather tea-party-inspired members who feel  beholden to their conservative base. So the key question over the next few weeks is whether the shutdown changed the political dynamics for the party based on a temporary dip in the polls.

Several aides across chambers and parties don’t know the answer to that question but doubt that much has changed for the tea party contingent. If the status quo prevails, the budget conference could become a meaningless footnote to this Congress, and a stopgap measure will be the only way to avoid another politically damaging shutdown.

Niels Lesniewski and Emma Dumain contributed to this report.