More than 100 human resources chiefs and dozens of the world's largest businesses on Thursday ramped up support for undocumented workers, signaling their opposition to the Trump administration's move to scuttle an immigration program that allows hundreds of thousands workers to be employed.

In a letter sent to Congress, chief human resource officers from major companies, including 21st Century Fox, Baker Hughes, Target, HP and Dow Chemical, pushed support for the Deferred Action for Childhood Arrivals program, which is now set to end in March. More than 700,000 immigrants are employed in the United States through the program, known as DACA.

Meanwhile, dozens of the largest companies and industry groups also announced a coalition urging action to protect the DACA program. The Coalition for the American Dream includes major technology companies, including Amazon, Apple and Facebook, and it also includes big names such as General Motors, Google, Hewlett Packard, IBM and Microsoft.

Earlier this year, Trump rescinded DACA, a program that allows undocumented workers who arrived in the United States as children to be protected from deportation. The HR Policy Association letter and the technology company coalition are the latest signs of outspoken opposition to the administration's policy change.

“We are concerned that the rhetoric around immigration issues often obscures the truth about how foreign-born workers of all skill levels benefit their companies, American workers, American communities, and the American economy,” according to the letter, organized by the HR Policy Association. “Further, while we believe the existing immigration laws need to be responsibly enforced, we are concerned that discouraging these workers' participation in the U.S. workforce through stricter policies would reduce productivity, intensify the ongoing workforce crisis, and disadvantage American businesses and their U.S. employees operating in the global economy.”

About three-fourths of major U.S. companies employ workers who are participating in DACA, according to a group formed by Facebook founder Mark Zuckerberg, Microsoft's Bill Gates and other heavyweights from the technology industry. FWD.us formed in 2013 by the tech giants to push for immigration reform. A report from the group found that canceling the program would mean 30,000 workers a month would lose jobs.

Other estimates show that companies would also face $6.3 billion in turnover costs. If DACA is rescinded without a replacement, companies could face fines, up to $20,000 per violation, for employing undocumented workers.

Under federal immigration law, a company can be at fault for employing an undocumented worker, not the employee.

The HR Policy Association's letter points to a report the group conducted that argues amid a workforce shortage, companies increasingly rely on foreign-born workers.

“America's international competitors understand that attracting workforce talent from around the world is vital to economic success, and many are rewriting their immigration policies accordingly,” the letter argues. “Some have gone so far as to say that the United States' reticent attitude toward foreign workers has created an opportunity for other countries to secure the economic benefits derived from those workers. As Congress and the administration consider proposals for changes in the immigration laws and/or enforcement strategies regarding existing laws, we urge you to consider these benefits to American workers, companies, communities, and the American economy.”

The group also released a white paper Thursday that presses the importance of the workforce shortage and the role foreign-born workers play.

The paper notes a survey by the Information Technology and Innovation Foundation that found those responsible for some of the most important innovations in the United States found that over a third are foreign-born while 17 percent are not U.S. citizens.

“Our own companies' experience has shown that foreign-born workers on work visas typically overperform in terms of innovation, creating new ways to increase productivity and developing new products such as invaluable medicines,” the paper notes. “Such contributions add to the American success story without detracting from it.”

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