WASHINGTON (AP) — Sen. Joe Manchin wavered Monday on his support for President Joe Biden’s sweeping $1.75 trillion domestic policy proposal, saying instead it’s “time to vote” on a slimmer $1 trillion infrastructure package that has stalled amid talks.

The West Virginia Democrat’s announcement comes as Democrats want a signal from Manchin that he will support Biden’s big package. He’s one of two key holdout senators whose votes are needed to secure the deal and push it toward passage.

Instead, Manchin rebuffed progressive Democrats, urging them to quit holding “hostage” the smaller public works bill 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.

Democrats have been working frantically to finish up Biden’s signature domestic package after months of negotiations, racing toward a first round of House votes possible later this week.

The White House swiftly responded that it remains confident Manchin will support Biden’s plan.

“Sen. 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 Sen. Manchin’s support.”

The stakes are high with Biden overseas at a global climate change summit and his party fighting in two key governors’ races this week — 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.

Progressives have been refusing to vote on the smaller public works bill, using it as leverage as they try to win commitments from Manchin and Democratic Sen. Kyrsten Sinema of Arizona, the other key holdout, for Biden’s broader bill.

Manchin, though, said he will “not support a bill that is this consequential without thoroughly understanding the impact” it has on the economy and federal debt. He wants Democrats to push ahead with the smaller public works bill of roads, highways and broadband projects that had already been approved by the Senate but is being stalled by House progressives as the broader negotiations are underway.

“This is not how the United States Congress should operate,” Manchin said. “It’s time our elected leaders in Washington stop playing games.”

Biden’s top domestic priorities have been a battlefield between progressive and moderate Democrats for months, and it was unclear if that timetable could be met.

The package 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 tax breaks encouraging cleaner energy and electrified vehicles.

Much of its costs would be covered with higher taxes on people earning more than $10 million annually and large corporations.

Rep. Pramila Jayapal, D-Wash., the leader of the progressive caucus, said she trusts that Biden will have the support needed for passage.

“I trust the president will deliver,” Jayapal said on CNN.

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

Talks were continuing and no final agreement had been reached. But the movement raised hopes that the party’s 10-year, $1.75 trillion measure would address the longtime Democratic campaign promise to lower pharmaceutical costs, though more modestly than some wanted.

Associated Press writer Alan Fram contributed to this report.