Railway unions previously halted a nationwide strike in September after the White House was able to reach a tentative agreement between unions and freight companies. However, after the nation’s largest rail union SMART Transportation Division rejected the deal last week, a strike is back on the table unless a new settlement can be reached by December 9.

The president is looking to “override the ratification procedures” in the ongoing deal despite the renewed strike threat, as several other rail unions have accepted the tentative deal that would raise wages by 24 percent over a five-year period as well as a $5,000 bonus for workers.

“As a proud pro-labor President, I am reluctant to override the ratification procedures and the views of those who voted against the agreement,” Biden said in a statement Monday. “But in this case—where the economic impact of a shutdown would hurt millions of other working people and families—I believe Congress must use its powers to adopt this deal.”

Biden added that a railroad shutdown would “devastate our economy,” saying many industries could risk shutting down without a running freight rail.

“My economic advisors report that as many as 765,000 Americans—many union workers themselves—could be put out of work in the first two weeks alone,” Biden said. “Communities could lose access to chemicals necessary to ensure clean drinking water. Farms and ranches across the country could be unable to feed their livestock.”

Among the demands from rail unions that rejected the tentative agreement include improving workers’ quality of life, such as increasing days allotted for paid time off and sick leave.

According to the Association of American Railroads, roughly 84 percent of rail workers are unionized, represented by 12 different unions. Biden’s tentative agreement in September was accepted by eight of them, reported NPR.

Last week, the Brotherhood of Maintenance of Way Employees Division (BMWED) released a statement that its members would also be ready to strike December 9 if a new deal fails to materialize, following SMART’s lead. According to the release, 55 perfect of all railway workers are represented by the four unions who have rejected the agreement.

“Over the last year, numerous employers throughout the world have analyzed what they could do to attract and retain talented employees,” BMWED President Tony Cardwell said in the release. “The railroads have done the complete opposite.”

Biden said in his statement Monday that he shares “workers’ concern about the inability to take leave to recover from illness or care for a sick family member,” adding that “no one should have to choose between their job and their health.”

“But at this critical moment for our economy, in the holiday season, we cannot let our strongly held conviction for better outcomes for workers deny workers the benefits of the bargain they reached, and hurl this nation into a devastating rail freight shutdown,” the president added.

Newsweek has reached out to SMART and BMWED for comment.

Update 11/28/22, 7:34 p.m. ET: This story has been updated with additional information and background.