Senate Majority Leader Mitch McConnell (R-Ky.) and other congressional leaders are trying to wrap up a deal by the middle of next week.  (AP Photo/J. Scott Applewhite, File)

The Senate on Thursday passed a stop-gap bill that would give negotiators until the middle of next week to reach a deal on a year-end spending bill, as congressional leaders slowly make progress toward an agreement.

The Senate quietly passed the short-term funding extension by voice vote and the House is expected to clear the legislation early on Friday, hours before funding for the government is set to run out.

“This short-term funding resolution allows time for the House and Senate to complete work on pending appropriations legislation,” said Senate Appropriations Committee Chairman Thad Cochran (R-Miss.). “Our negotiations are progressing steadily, and I expect that senators will soon be able to consider a bill that will meet the funding needs for our national defense and other priorities.”

The pressure is now on negotiators to reach an agreement quickly in order to allow the House and Senate enough time to approve the deal before the new Dec. 16 deadline.

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Negotiators plan to work through the weekend and a vote on any deal could occur as early as Monday. House Appropriations Committee Chairman Harold Rogers (R-Ky.) would not say when he expects to release the text of a deal, but he did not rule out the possibility it could be unveiled Sunday.

Sen. Roy Blunt (R-Mo.), a junior member of Senate Majority Leader Mitch McConnell’s leadership team, said it is now up to top leaders to reach an agreement.

“Most people have determined that there’s not much they can do about these final negotiations,” Blunt said. “That’s probably finally set in that this is going to be decided by three or four people and most of us are not one of those three or four people.”

Rogers told reporters Thursday morning that the negotiations had “moved inches” in the past 24 hours but high-level issues, like whether to combine the omnibus spending bill with a package of tax breaks, still need to be resolved.

“We’re not close to a [touchdown],” Rogers said after a weekly closed-door meeting of House Republicans. “Even the five day extension is going to be really close.”

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For days the talks have been at an impasse as party leaders attempt to trade priorities across the spending bill and an effort to extend around 50 expired tax breaks.

Congress routinely reauthorizes the breaks for a year or two at a time, but negotiators are considering a proposed agreement that would permanently extend several tax provisions– including the research and development credit, expensing rules for small businesses, the Child Tax Credit (CTC), the earned income tax credit (EITC) and the American Opportunity Tax Credit for college expenses — while extending the others for five years.

The two must-pass bills are the last chance Republicans and Democrats have this year to force a pet policy issue into law. Republicans have been working to attach dozens of unrelated policy riders to the spending bill and Democrats want concessions on the tax legislation.

Several members from both parties privately acknowledged that much of the backroom dealings have come down to working out an agreement that allows both parties to walk away with some concessions.

Republicans want use the spending bill to roll back environmental regulations, repeal a decades old ban on crude oil exports and kill portions of the 2010 Dodd-Frank Wall Street Reform bill.

Democrats want to end tax breaks for oil and gas producers and permanently expand and extend tax breaks for low-income workers.

Senate Minority Whip Dick Durbin (D-Ill.) said on Thursday that Democrats do not want to allow the oil export ban to be lifted. Durbin would not commit to a direct trade on the tax side but he said ending some breaks for the profitable industry would be a reasonable request.

“There is strong feeling that something that’s worth up to $200 billion to the oil industry ought to be of some value to the rest of America too,” Durbin said. “I think this is a very profitable industry and this will add to their profitability and paying more into sustaining our nation and helping it grow is not unreasonable. “

On Thursday, House Minority Leader Nancy Pelosi (D-Calif.) announced that she wants to reinstate funding for the federal government to research the impact of gun violence.

“The American people deserve the facts,” Pelosi said in a statement. “Members of Congress need the data.”

House Speaker Paul D. Ryan (R-Wisc.) declined to take a position on the request, but several aides speculated that it could be an area of compromise.

There has been increasing support for the research in recent months, including from former Rep. Jay Dickey (R-Ark.) who sponsored the policy rider in 1995 that still bans federal funds for gun violence studies. Dickey has said repeatedly that he regrets the amendment and did not anticipate its consequences.

More than 100 House Democrats signed a letter asking for funding for the research to be reinstated and more than 2,000 doctors organized by the group Doctors for America wrote to Congress making the same request.

Ryan was calm about prospects for a deal on Thursday, though he would not specify when he thinks the work will be complete.

“I don’t think it would be right to say what date we’re going to be done by because I want to make sure that these negotiations are done well and done right, and not by some arbitrary deadline,” he said. “We’re trading offers. We’re talking to each other. We’re doing all of the things that you would do, the appropriators and the leaders, so that we can get to an agreement.”