Some 1,900 leading researchers accused the Trump administration in an open letter on Monday of conducting a “wholesale assault on U.S. science” that could set back research by decades and that threatens the health and safety of Americans.

The letter’s signatories, all of them elected members of the National Academies of Sciences, Engineering and Medicine, warned of the damage being done by layoffs at health and science agencies and cuts and delays to funding that has historically supported research inside the government and across American universities.

“For over 80 years, wise investments by the U.S. government have built up the nation’s research enterprise, making it the envy of the world,” the letter said. “Astoundingly, the Trump administration is destabilizing this enterprise by gutting funding for research, firing thousands of scientists, removing public access to scientific data and pressuring researchers to alter or abandon their work on ideological grounds.”

The letter said that many universities and research institutions had so far “kept silent to avoid antagonizing the administration and jeopardizing their funding.” But, it said, “the nation’s scientific enterprise is being decimated.”

The signatories called on Americans to appeal to Congress to protect scientific funding.

With Elon Musk’s efforts to cut spending and President Trump’s crackdown on institutions he sees as ideological enemies, the administration has sought to dismantle parts of the federal government’s scientific funding apparatus.