Senators are close to reaching an agreement on a $10 billion coronavirus relief package, putting Congress on track to deliver funding that Democrats had hoped to pass weeks ago.

However, some members of the majority party are dissatisfied with the compromise reached with Republicans, warning that the loss of global aid will have ramifications and putting the package’s fate in jeopardy in the House.

The total — the result of days of back-and-forth between senior senators from both parties — would leave out a key demand from the White House. Many Democrats have raised concerns about the country’s preparedness to fight the pandemic abroad because it does not include $5 billion for global vaccine efforts.

Sen. Tim Kaine (D-Va.) said, “My understanding is there’s a deal, and we’ll get briefed on it at lunch,” adding that he was “very upset” that billions in global vaccine funds would be excluded. “That was a huge opportunity squandered.”

Attempting to break a filibuster in the Senate will require the support of at least ten Republicans, a vote that Majority Leader Chuck Schumer could call up next week — early hopes for a test vote on Thursday dimmed by midday. Meanwhile, Supreme Court nominee Ketanji Brown Jackson will be the focus of next week’s floor schedule, heightening the potential urgency of a vote.

Sen. John Cornyn (R-Texas) said of the closed-door negotiations, “They’re pretty close to working out a deal on $10 [billion]. $10 billion is a lot of money.”

After an earlier version of the aid package failed in the House due to objections from several Democrats over how to pay for it, key senators from both parties began working on a revised version this week. Senators Mitt Romney (Utah), Roy Blunt (Mo. ), Richard Burr (N.C.), and Lindsay Graham (S.C.) have been in close contact with Schumer (S.C.). Senators Patty Murray (D-Wash.) and Chris Coons (D-Del.) were also involved in the talks.

Senators clarified that there are still some stumbling blocks to overcome before a vote on the Senate floor. Romney stated that they are still awaiting a score from the Congressional Budget Office, while Murray stated that the total amount is still in flux and that it is too early to declare their work completed.

“A deal isn’t a deal until we have signatures on a piece of paper in the United States Senate,” he said. “I can say that everyone is trying to come up with a way to get something passed,” Murray said.

The entire package could clear the chamber in the coming days and be sent to the House, where many Democrats are furious at the plan to drastically reduce the package’s size.

“I believe the Republicans either don’t care or don’t know what they’re doing. However, it is incorrect,” Speaker Nancy Pelosi told reporters on Thursday, though she did not rule out a scaled-back version.

Several House Democrats have already threatened to vote no on a pandemic bill if the $5 billion in global vaccination funds are not included. Even if they are unable to reach an agreement on a higher price, several lawmakers have stated that they will demand that at least some of the funds go toward international health initiatives.

On Wednesday, Republican senators floated a $10 billion aid package, reducing a previously negotiated $15.6 billion aid package that failed in the House earlier this month. It’s also significantly less than the White House’s initial request of nearly $22.5 billion, which included requests for tests, therapeutics, and vaccines, including vaccines for children under the age of five, which could be approved in the coming months.

The White House has increased the pressure on Congress to deliver quickly after the initial Covid funding deal fell apart. With another possible Omicron wave on the horizon, officials have repeatedly warned that they don’t have the funds to restock vaccines, among other pressing needs.

During a closed-door meeting of lawmakers earlier Thursday, Pelosi, among other Democrats, expressed concern about the Senate’s plan to trim the package’s size, according to multiple people in the room.