The National Institutes of Health pledged Tuesday at a private meeting of scientists who use fetal tissue that the government’s largest funder of biomedical research would continue to support such work despite a conservative broadside against it.

The commitment by top Health and Human Services and NIH officials to continue funding for researchers who work for nongovernment labs came at the end of a seven-hour meeting with about 40 scientists from around the country, according to three participants.

Those scientists were part of an invitation-only workshop to evaluate the politically loaded question of whether adequate alternatives exist to fetal tissue in studies pursuing treatment and possible cures for such diseases as HIV, Zika and cancers. The workshop was part of a broad audit being conducted by the Department of Health and Human Services, which oversees NIH, as antiabortion activists and other social conservatives reactivate a years-old opposition to it.

Toward the meeting’s end, one of the invited scientists, Stanford University researcher Irving Weissman, who participated remotely, pressed officials about their intentions. “I want to know the bottom line” about future funds, Weissman recounted in an interview afterward. Brett Giroir, HHS’s assistant secretary for health, replied that, at least for grants and contracts for researchers employed by universities and nongovernment labs, there will be no pause as long as experiments comply with the ethical guidelines of their universities and the federal government, as well as state laws, Weissman said.

The future of NIH’s spending on fetal tissue research in its own labs sounded less clear, according to the participants. At one point,Giroir, who has played a lead role in the fetal tissue reconsideration, told the scientists that the question was still being reviewed, one participant said.

At another point, Giroir said that any alternative sources of tissue “must be as predictive, as reliable and as validated as existing models” that use fetal tissue, according to another participant, Mike McCune, a longtime HIV researcher who is a senior adviser to the Bill and Melinda Gates Foundation.

The consensus of the meeting, also led by Daniel Rotrosen, director of NIAID’s Division of Allergy, Immunology and Transplantation, was that no such models exist, McCune said Wednesday.

NIH officials summarized the discussion in a public statement Wednesday. “There was strong opinion that work should proceed on a variety of models derived with fetal tissues or from alternative sources,” it said, adding the synopsis “is not intended to pre-judge the outcome of the HHS audit.”

The gathering at NIH’s main campus in Bethesda, Md., was convened as the Trump administration is being pressed by conservative members of Congress and conservative organizations aligned with the president to end government support for research that implants snippets of tissue from elective abortions into mice for laboratory studies.

McCune and other scientists said they emerged from the meeting pleased their views were heard.

Though HHS officials have said repeatedly that no changes to funding policy would be made until the audit is completed, the administration has taken actions lately that have stoked researchers’ fears. In September, it ended a small contract with a California firm that supplies scientists with the tissue. And federal officials told the lead researcher at an NIH lab in Montana that he could not procure fetal tissue for his longtime work on HIV.

Early this month, NIH decided not to extend for another year a long-term contract with a lab at the University of California at San Francisco that uses fetal tissue in mouse studies of promising HIV therapies. NIH then pivoted and gave the university a 90-day extension.

The Montana researcher, Kim Hasenkrug, attended Monday’s workshop. He has been forbidden by federal officials to discuss his lab’s funding, but other participants said officials told Hasenkrug they would continue to support his work.

Rotrosen also said that the 90-day extension would be lifted from the UCSF lab and that its funding would continue as long as the work met NIH rules and the university’s informed-consent guidelines, according to a workshop participant.

NIH this month issued a notice that it will devote $20 million to research trying to advance alternative models to fetal tissue.

Antiabortion activists, meanwhile, sought to ratchet up pressure on NIH. Marjorie Dannenfelser, president of the antiabortion Susan B. Anthony List, said that officials “have jumped ahead of the administration’s ongoing audit process” and, if their commitments stand, it “would be the first time the Trump administration has broken with the pro-life movement.”

Others renewed calls for the institutes’ director, Francis Collins, to resign following reports he had told an NIH advisory committee that fetal tissue research would remain “a mainstay.” Collins describes himself as an evangelical Christian and has said his faith would not influence science policy.

Correction: An earlier version of this story incorrectly identified the official who said the federal government would continue to fund fetal tissue research by non-governmental scientists. The person who made that commitment was Brett Giroir, HHS’s assistant secretary of health, not Daniel Rotrosen, director of NIAID’s Division of Allergy, Immunology and Transplantation. The story has been corrected.