Sen. Joe Manchin III said on Sunday that he can’t support the sweeping social safety net and climate change package that President Joe Biden and Democratic leaders have made their top legislative priority.

The West Virginia Democrat’s opposition is likely the final nail in the coffin for the massive $2 trillion-plus “Build Back Better” legislation, given the Senate’s 50-50 split, unless extensive changes are made that would result in key provisions being scuttled.

“I can’t vote for it, and I cannot vote to continue with this piece of legislation,” Manchin told “Fox News Sunday.” “I just can’t. I’ve tried everything humanly possible. I can’t get there … This is a ‘no.’”

Manchin had been negotiating directly with Biden last week, who issued a statement Thursday saying they couldn’t reach agreement in time to take up the measure before the holidays. Biden said he would continue working with Manchin and Democratic leaders to finalize a bill “over the days and weeks ahead.”

[Biden, Democrats punt reconciliation, voting rights bills to January]

Manchin has expressed several concerns with the size and scope of the package. He wants the total price tag capped at $1.75 trillion over 10 years and has complained that several programs would end early in order to artificially keep costs down. The expanded child tax credit, for example, would be renewed for one year at a $185 billion cost, when Democrats have been up front about wanting it made permanent, which under current law could cost up to $1.6 trillion.

“Pick what [your] prized priorities are, like most people do in their families or their businesses, and you fund them for 10 years. And you make sure they deliver the services for 10 years,” Manchin said.

In a follow-up statement after the Fox News interview, Manchin cited the ongoing pandemic, rising inflation and “geopolitical uncertainty” as reasons to move on from the reconciliation bill and focus elsewhere.

“I have always said, ‘If I can’t go back home and explain it, I can’t vote for it,’” Manchin said. “Despite my best efforts, I cannot explain the sweeping ‘Build Back Better Act’ in West Virginia and I cannot vote to move forward on this mammoth piece of legislation.”

‘Sudden and inexplicable’

White House spokeswoman Jen Psaki later issued a statement saying Manchin’s comments “represent a sudden and inexplicable reversal in his position, and a breach of his commitments to the president and the senator’s colleagues in the House and Senate.”

Psaki said Manchin had delivered a written proposal to the White House last Tuesday for a scaled-back bill that was “missing key priorities” but was viewed as a framework that could ultimately lead to a compromise.

Psaki made clear the administration would continue to fight for passage. “Just as Sen. Manchin reversed his position on Build Back Better this morning, we will continue to press him to see if he will reverse his position yet again, to honor his prior commitments and be true to his word,” she said.

Manchin’s opposition also pulls the rug out from under progressives who agreed to support the bipartisan infrastructure law Manchin helped to write on condition that the Build Back Better bill would ultimately have enough support to pass in both chambers.

“All I want for Christmas is a senator that has compassion for the American people and not contempt,” Rep. Ayanna S. Pressley, D-Mass., said Sunday on CNN. “I had great concerns, and I take no joy in those fears playing out in real time, that by decoupling these bills, that we would cede all of our leverage. And that had everything to do with my credible concerns, based on lived experience, with Sen. Manchin changing the goalposts continually.”

Senate Budget Chairman Bernie Sanders, I-Vt., in a separate CNN interview Sunday said Manchin is “going to have a lot of explaining to do to the people of West Virginia.”

Party leaders have pointed out how many child tax credit beneficiaries live in West Virginia, for instance. And Sanders cited provisions intended to rein in the cost of prescription drugs, expand home health care options and add hearing benefits to Medicare as important in Manchin’s home state.

Sanders added that Senate leaders should bring a bill to the floor anyway and dare Manchin to vote against it.

“I would hope we would have had 50 Democrats. But if that is the case, then I hope that we will bring a strong bill to the floor of the Senate as soon as we can and let Mr. Manchin explain to the people of West Virginia why he doesn’t have the guts to stand up to powerful special interests,” Sanders said. “We’ve been dealing with Mr. Manchin for month after month after month. But if he doesn’t have the courage to do the right thing for the working families of West Virginia and America, let him vote ‘no’ in front of the whole world.”