WASHINGTON (AP) — Pushing to regain momentum, House Speaker Nancy Pelosi said privately Tuesday she expects to finish a final draft of President Joe Biden’s sweeping $1.75 trillion domestic proposal by midday and pave the way for voting as soon as Thursday, according to her remarks at a closed-door caucus meeting.

Democrats are working frantically to wrap up Biden’s big bill after pivotal Sen. Joe Manchin interjected fresh uncertainty by publicly wavering over whether or not he would support the party’s ambitious effort. The president has no votes to spare as Democrats try to push his legislative package to expand health care, child care, and other social services and tackle climate change into law.

Pelosi told Democrats at Tuesday’s morning caucus meeting that “hopefully by midday” they will be able to “freeze” the design of the bill. She said leaders are waiting for Manchin and another key Democrat, Sen. Kyrsten Sinema of Arizona, to weigh in on final provisions over climate change and lowering prescription drug costs, and that immigration provisions remain in flux.

Pelosi said the next step is to bring the Biden package to the Rules Committee on Wednesday — which would pave the way for a vote as soon as Thursday on the bill as well as a companion $1 trillion infrastructure package. The remarks were conveyed by a person familiar with her comments who requested anonymity to share the private meeting.

Exiting the meeting, Pelosi said she was not making any announcements on vote timing.

“I think we’re going to pass both bills — hopeful this week if we get the differences that are still outstanding resolved,” Majority Leader Steny Hoyer, D-Md., said at the Capitol.

Tensions are running strong in the rush to finish up after months of endless negotiations. The stakes are particularly high with Biden overseas at a global climate change summit and his party fighting in two key governors’ races Tuesday — in Virginia and New Jersey — that are seen as bellwethers in the political mood of the electorate.

With Republicans staunchly opposed and no votes to spare, Democrats have been trying to unite progressive and centrist lawmakers around Biden’s big vision.

Blame is pointing all around as progressive and centrist lawmakers, particularly holdouts Manchin and Sinema, have fought over details of the sprawling 1,600-page package and been unable to seal a deal.

On Monday, Manchin stunned Washington when he announced he still had trouble with the far-reaching package and its impact on the economy and everyday lives.

Rather than providing assurances to his progressive colleagues that he was on board, the West Virginia senator reiterated his concerns. He then urged progressives to quit holding “hostage” a smaller $1 trillion public works bill they have refused to support, withholding it as leverage as negotiations continue on the broader package.

“Enough is enough,” Manchin said at a hastily called news conference at the Capitol.

Manchin said he’s open to voting for a final bill reflecting Biden’s big package “that moves our country forward.” But he said he’s “equally open to voting against” the final product as he assesses the sweeping social services and climate change bill.

It’s unclear whether Manchin’s resistance will deliver a debilitating blow to those efforts or have the opposite effect of propelling Democrats to start taking votes on Biden’s signature domestic proposal. His comments infuriated some Democrats but energized others, particularly progressives eager to force his hand.

The White House swiftly responded that it remains confident Manchin will support Biden’s plan, and the congressional leaders said it all remained on track.

“Senator Manchin says he is prepared to support a Build Back Better plan that combats inflation, is fiscally responsible, and will create jobs,” said press secretary Jen Psaki in a statement. “As a result, we remain confident that the plan will gain Senator Manchin’s support.”

Pelosi and Senate Majority Leader Chuck Schumer both echoed the White House. And progressives insisted it’s time to vote.

Rep. Pramila Jayapal, D-Wash., the leader of the progressive caucus said, “I don’t know what Sen. Manchin is thinking, but we are going to pass both bills through the House and we are going to deliver transformative change to the people.”

Biden unveiled a framework for the package last week, a sizable investment in social service programs and climate change strategies, but Democrats are trying to negotiate a provision to lower prescription drug prices for seniors with Medicare, among other final changes.

Sen. Ron Wyden, D-Ore., told reporters late Monday there could be a new $2,000 limit on out-of-pocket drug costs for seniors with Medicare as well as lower prices for insulin under changes being negotiated to the program’s Part D.

Many Democrats were livid at Manchin for hitting the brakes yet again, particularly because they argued that Biden’s plan is expected to be fully paid for with new taxes on companies and the wealthy, and not add to the debt.

“I think he just betrayed his lack of seriousness,” said Rep. John Yarmuth, D-Ky., the chairman of the Budget Committee.

The $1.75 trillion package is sweeping in its reach and would provide large numbers of Americans with assistance to pay for health care, education, raising children, and caring for elderly people in their homes. It also would provide some $555 billion in tax breaks encouraging cleaner energy and electrified vehicles, the nation’s largest commitment to tackling climate change.

Much of its costs would be covered with higher taxes on people earning over $10 million annually and large corporations, which would now face a 15% minimum tax in efforts to stop big businesses from claiming so many deductions they end up paying zero in taxes.

Over the weekend, Democrats made significant progress toward adding provisions curbing prescription drug prices to the massive package, two congressional aides said Sunday. They requested anonymity to discuss the ongoing negotiations.

And pharmaceutical makers would have to pay a rebate if their prices rise above certain markers.

Some moderate Democrats in the House said they want to see see the final assessment from the Congressional Budget Office, which will offer a nonpartisan assessment of the overall bill’s entire budgetary costs, before taking the vote.