PITTSBURGH (TNS) — As hundreds of U.S. Steel employees rallied Downtown on Wednesday to show their support for a proposed sale to Nippon Steel, the CEO of the Pittsburgh steelmaking icon warned that local jobs would be lost if the deal falls through — and that the company may move its headquarters out of Pittsburgh.

The rally played out as President Joe Biden was preparing to announce that he will formally block the deal, according to media reports — even as the estimated 400 steelworkers showed their support for Nippon outside the U.S. Steel Tower with signs reading “People over Politics” and “Nearly $3B reasons to say yes.”

“You have a company not just promising investment in these plants, but investments in the people,” Braddock Borough Councilwoman Chardae Jones said at the rally. “I’ve had my qualms with U.S. Steel, but I know when to stand with them.”

Wednesday morning, David Burritt, U.S. Steel’s president and chief executive officer, said in a release that “we want elected leaders and other key decision makers to recognize the benefits of the deal as well as the unavoidable consequences if the deal fails.”

“In addition to moving away from integrated steelmaking, the lack of a deal with Nippon Steel raises serious questions about U.S. Steel remaining headquartered in Pittsburgh,” the company said in the release.

Nippon agreed in December to buy U.S. Steel for $14.9 billion and has since pledged to spend $2.7 billion fixing up steel plants, including investing at least $1 billion in the Mon Valley. But the deal has faced stiff political opposition.

Republican presidential candidate and former President Donald Trump has said he would block the deal, and Biden came out against it during an April visit to Pittsburgh. On Monday, Democratic presidential candidate and Vice President Kamala Harris used her Labor Day appearance in Pittsburgh to call for U.S. Steel to remain a U.S.-owned and operated company.

“U.S. Steel is a historic American company,” Harris said. “It is critical for our nation to maintain strong American steel companies. U.S. Steel should remain American-owned and American-operated.”

The United Steelworkers union leadership has also opposed the deal, unmoved by Nippon Steel’s promises of job protections and an influx of capital.

But U.S. Steel cautioned Wednesday that “without the Nippon Steel transaction, U.S. Steel will largely pivot away from its blast furnace facilities, putting thousands of good-paying union jobs at risk, negatively impacting numerous communities across the locations where its facilities exist, and depriving the American steel industry of an opportunity to better compete on the global stage.”

The Committee on Foreign Investment in the United States and the U.S. Department of Justice are reviewing the sale to make sure it doesn’t establish a monopoly or threaten national security.

The news that Biden intends to block the transaction, first reported by the Washington Post, came just minutes after the Downtown rally wrapped up and before any speakers had time to react. It sent shares of U.S. Steel sinking 17.5%.

The White House declined to comment but said in a statement that the Committee on Foreign Investment had not yet sent its recommendation to the president. Nippon Steel declined to comment on speculation about Biden’s decision.

Many legacy workers at the rally expressed hope that Nippon’s deep pockets would allow steel operations to continue in the Mon Valley for decades.

“My son interviewed three weeks ago,” said Greg Snyder, a company supervisor in Clairton. “That would be the third generation.”

Local elected officials joined U.S. Steel employees in describing the deal as a rare opportunity that should not be passed up. They also expressed fear about what could happen to the region if it falls through.

Rob Kopf, vice president of sales, said he witnessed firsthand “the near fatal destruction endured by numerous communities here” when plants closed in the 1980s.

“Today we have a chance to make sure that same fate is not suffered by Braddock, Clairton and West Mifflin, the three towns which make up our Mon Valley Works,” he said.

Most exciting to many workers was Nippon’s promise to build a hot strip mill as part of the $1 billion investment in the Mon Valley. Senior Vice President Scott Buckiso said the company had talked about a new hot mill since he started as a shift manager in 1990.

“This is something that makes all of us stronger,” said Sam DeMarco, Allegheny County councilman-at-large. “We can’t afford to miss this opportunity. We must support this investment. We must get this deal done.”

Other speakers said they were “baffled” by the level of political opposition to the sale.

“It goes against every ounce of common sense that I have,” Kopf said, gesturing to the “people over politics” signs.

Jones, the Braddock councilwoman, addressed that concern directly.

“People are out here politicizing our poverty in the Mon Valley,” she said. “I urge people, before they make up their minds about this potential sale, to take a walk through my neighborhood.”

West Mifflin Mayor Chris Kelly underscored the point: “I’m wondering why more people aren’t pissed at the politicians using these people in the Mon Valley as pawns,” he said. “Whether you’re a Democrat or Republican, you should be upset, and you should let them know it.”

One U.S. Steel employee, who declined to be named, noted that both presidential candidates have come out against the deal, meaning that “if I want to keep my job for the long term, I got nobody I can vote for.”

Kelly said he had personally called U.S. Sen. John Fetterman, D-Pa., who opposes the sale, to try to change his mind. Fetterman reacted Wednesday by using an expletive to decry U.S Steel leadership. “As I’ve always said, I will follow and stand with the United Steelworkers against the shameless executives looking for a golden parachute,” the senator said in a statement.

Others echoed Fetterman.

Rep. Chris Deluzio, D-Aspinwall, said in a statement on X that U.S. Steel has “repeatedly shown that they do not respect the union steelworkers who built the company.”

“And now they threaten to close the Pittsburgh headquarters and the Mon Valley Works,” he said. “At every juncture, they’ve neglected investments in Western PA and other strong union regions in favor of investment in facilities in anti-union states with non-unionized workforces. They can dress it up however they want, but their cartoonish anti-union behavior puts them in good company with the robber barons they mimic: their business model seems to be about breaking the union.”

U.S. Sen. Bob Casey, D-Pa., in a post on X called Burritt’s statements “a slap in the face to the steelworkers whose skill and work ethic make the company successful and to the people of Southwestern Pennsylvania whose livelihoods rely on the steel industry.”

He said his priority is to keep union steel jobs in the Mon Valley.

“I encourage Mr. Burritt to come to the table and work with the steelworkers to protect and keep these jobs in Pennsylvania where they belong,” he said.

While many speakers at the rally touted their former membership in the United Steelworkers union, none of them is a current member.

The crowd appeared to be a mix of union and nonunion employees. Some employees told the Post-Gazette they were frustrated that the union hadn’t gotten on board with the sale.

“We are all part of the same family,” said Buckiso.

Earlier in the day, the union bashed the rally as a “pathetic attempt” to save a “merger on life support.” The USW also decried Burritt’s warnings of job losses and an exit from Pittsburgh as “baseless and unlawful.”