Senate Minority Leader Chuck Schumer (D-N.Y.) added that “while many, if not all, of the difficult topics are behind us, a few final issues must be hammered out. We’re very close to an agreement but the details really matter.”

Though negotiators said they were close, a short-term resolution now looks like more likely to avoid a government shutdown on Friday at midnight and keep Congress working through the weekend to finish its work for the year. McConnell said working on Saturday and Sunday was now “highly likely.”

“It’s looking like more and more of a real possibility we’ll have to do a short-term [spending bill]. We want to keep the pressure on as long as we can. I hope it won’t be more than 24 to 48 hours,” said Senate Majority Whip John Thune (R-S.D.). “I really think this is coming to a close, but as you know once you get the agreement and you’re drafting up, the language matters.”

Top aides are discussing a bill to keep the government funded until Sunday to allow for further talks and drafting of the rescue package. It could easily take a couple days for the House and Senate to finish drafting the legislation —which is expected to be a massive $1.4 trillion omnibus couple with around $900 billion in coronavirus relief — and pass it.

Congressional leaders are optimistic about cutting a deal and ending the lame duck session within days, so there could be little room to maneuver without another short-term spending bill. But congressional leaders have not publicly announced a deal or legislative text even as they remain optimistic about the state of play.

“We made some progress this morning, waiting to hear back,” Speaker Nancy Pelosi told reporters as she entered the Capitol Thursday morning.

Notably, McConnell and Schumer did not immediately take to the floor on Thursday morning as lawmakers continued trading offers.

“That the leaders didn’t open the session tells me they must be doing something this morning. I’m hoping it’s on Covid,” said Senate Minority Whip Dick Durbin (D-Ill.). “Everybody has a strong appetite to pass this, pass the omnibus and go home.”

The House and Senate would both need to approve the year-end funding bill and the coronavirus package, and in the Senate any one member can delay passage. Even if a deal is reached Thursday, it could take a day to draft the legislation.

The coronavirus package will include a new round of roughly $600 stimulus checks, beefed up unemployment benefits of $300 a week, about $325 billion for small businesses and money for transportation, vaccine distribution and schools, according to lawmakers and aides. Leaders are hopeful it will be married with the omnibus spending bill funding the government through September and have held off on releasing the text as the continue to haggle over coronavirus provisions.

Pelosi and Schumer held a call late Wednesday night with Treasury Secretary Steven Mnuchin over the ongoing talks.

Republicans are currently pushing back against several key Democratic requests in the rescue package. Democratic negotiators — Schumer and Pelosi — are asking for as much as $90 billion for governors to spend on health-care related concerns, which they say will help with vaccine distribution, while Republicans are terming that an unnecessary slush fund.

The GOP negotiators also remain opposed to a $1 billion pot of money for FEMA to deal with Covid-related emergencies. That same pot of money passed the House easily earlier this year. Democrats are pushing back against Republicans’ desire to wind down the Federal Reserve’s emergency lending program and are pressing for as much as $17 billion to venues and for more money for public transit.