The White House and Senate Republicans are working to finalize a coronavirus relief package ahead of a Monday rollout.

Treasury Secretary Steven Mnuchin and White House chief of staff Mark Meadows were back in the Capitol on Sunday for a second day of meetings with GOP staff as they work to lock down the forthcoming proposal.

As he left the Capitol, Meadows told reporters that they had "been working through just some of the technical language" and had reached "an agreement in principle."

"We have a few modifications that we're looking for clarity on, but we've gotten those down to a handful that hopefully will be resolved in the next hour or so," he added.

He also said he expected the remaining open issues to be "resolved" before Republicans introduce their package Monday.

"It's just down to a handful of items where we believe a phone call here and there should be able to resolve it," he added.

Mnuchin said there were "no outstanding issues" but noted that "there's some language that people are just double-checking."

Senate Republicans are expected to unveil their roughly $1 trillion proposal on Monday after punting last week amid ongoing negotiations with the White House on key provisions of the package. 

"The administration has requested additional time to review the fine details, but we will be laying down this proposal early next week. We have an agreement in principle on the shape of this package," Senate Majority Leader Mitch McConnell (R-Ky.) said from the Senate floor about the decision.

The package is expected to include $105 billion for schools, $16 billion in new testing money, more flexibility for how states and local governments can use $150 billion appropriated by Congress in March, and a five-year shield from coronavirus lawsuits except in the case of gross negligence or intentional misconduct. 

It's also expected to include a second round of stimulus checks. Mnuchin has said it will mirror the language in the March bill that provided a one-time check of $1,200 to individuals who make up to $75,000 per year. The amount of the check was scaled down until it hit an income ceiling of $99,000 per year for an individual, where it was phased out altogether. 

Republicans are also expected to nix the $600-per-week increase in unemployment benefits from the March bill, which began to expire on Saturday. 

Instead, they are proposing a system that would match the unemployment benefits to approximately 70 percent of what a person was making before being laid off, according to Mnuchin.

States have warned that it could take weeks or months to transition to the new system, given the antiquated technology in many offices. Some Republican lawmakers have said there needs to be a transition period during which the federal government would provide a flat amount per week, potentially $200. 

Both Mnuchin and Meadows declined on Sunday to get into details of the unemployment language beyond providing a 70 percent match. 

The introduction of the GOP proposal is expected to mark the start of bipartisan negotiations, which will likely be largely carried out by administration officials shuttling between leadership offices. 

Meadows and Mnuchin met with House Speaker Nancy Pelosi (D-Calif.) and Senate Democratic Leader Charles Schumer (D-N.Y.) last week, but both sides acknowledged they were waiting on text from Senate Republicans. 

Congress is under a tight time frame to craft an agreement without the talks spilling into the August recess. 

The House had been expected to leave on Friday, July 31, until early September. But House Majority Leader Steny Hoyer (D-Md.) has warned members to keep their travel plans for the first week of August flexibile, and Pelosi reiterated on Sunday that lawmakers could not leave Washington, D.C., without a deal. 

“We can’t go home without” a deal, she told CBS's "Face the Nation." “It’s so sad that people should have this uncertainty in their life.” 

Meadows and Mnuchin, during separate TV interviews on Sunday, floated the idea of passing a "skinny" relief bill that would pair the unemployment piece with one or two other issues such as school funding and liability protection. 

"I see us being able to provide unemployment insurance, maybe a retention credit to keep people from being displaced or brought back into the workplace, helping with our schools,” Meadows told ABC’s “This Week.”

"If we can do that along with liability protection, perhaps we put that forward and get that passed as we can negotiate on the rest of the bill in the weeks to come," he added.

Pelosi previously rejected the idea of breaking the next coronavirus bill into pieces. Meadows told reporters late last week that he was floating the idea without Pelosi or McConnell weighing in first. 

“We cannot piecemeal this," Pelosi told reporters late last week.