WASHINGTON — In his confirmation hearings to lead the National Institutes of Health, Jay Bhattacharya pledged his openness to views that might conflict with his own.

“Dissent,” he said, “is the very essence of science.”

That commitment is being put to the test.

On Monday, scores of scientists at the agency sent their Trump-appointed leader a letter titled the Bethesda Declaration, challenging “policies that undermine the NIH mission, waste public resources, and harm the health of Americans and people across the globe.”

It says: “We dissent.”

In a capital where insiders often insist on anonymity to say such things publicly, 92 NIH researchers, program directors, branch chiefs and scientific review officers put their signatures on the letter — and their careers on the line. An additional 250 of their colleagues across the agency endorsed the declaration without using their names.

The letter, addressed to Bhattacharya, also was sent to Health Secretary Robert F. Kennedy Jr. and members of Congress who oversee the NIH. White House spokesman Kush Desai defended the administration’s approach to federal research and said President Donald Trump is focused on restoring a “Gold Standard” of science, not “ideological activism.”

The letter came out a day before Bhattacharya is to testify to a Senate committee about Trump’s proposed budget, opening him to questions about the broadside from declaration signers, and it stirred Democrats on a House panel to ask the Republican chair for hearings on the matter.

The signers went public in the face of a “culture of fear and suppression” they say Trump’s administration has spread through the federal civil service. “We are compelled to speak up when our leadership prioritizes political momentum over human safety and faithful stewardship of public resources,” the declaration says.

Bhattacharya responded to the declaration by saying it “has some fundamental misconceptions about the policy directions the NIH has taken in recent months,” such as suggestions that NIH has ended international collaboration.

“Nevertheless, respectful dissent in science is productive,” he said in a statement. “We all want the NIH to succeed.”

Named for the agency’s headquarters location in Maryland, the Bethesda Declaration details upheaval in the world’s premier public health research institution over the course of months.

It addresses the termination of 2,100 research grants valued at more than $12 billion and some of the human costs that have resulted, such as cutting off medication regimens to participants in clinical trials or leaving them with unmonitored device implants.

In one case, an NIH-supported study of multidrug-resistant tuberculosis in Haiti had to be stopped, ceasing antibiotic treatment midcourse for patients.

In a number of cases, trials that were mostly completed were rendered useless without the money to finish and analyze the work, the letter says.

“Ending a $5 million research study when it is 80% complete does not save $1 million,” it says, “it wastes $4 million.”

The signers said they modeled their indictment after Bhattacharya’s Great Barrington Declaration in 2020.