The Trump administration faced mounting legal pressure on Saturday over its termination of hundreds of National Institutes of Health research grants. Court filings showed political considerations alone guided which projects lost funding, with plaintiffs including academic researchers and public-health advocates citing the documents in ongoing federal litigation.

The filings indicated that Department of Health and Human Services officials flagged grants tied to diversity, gender and vaccine hesitancy for cancellation regardless of scientific merit. Several universities reported the cuts halted clinical trials and left early-career scientists without support.

The American Association of Medical Colleges and university research groups have argued in court that the terminations violated federal administrative law by ignoring peer-review standards. A federal judge in Massachusetts previously ruled that some cancellations were unlawful, with further hearings expected in the coming weeks.

HHS has defended the decisions as consistent with the administration's priorities and lawful exercise of agency discretion. Department officials said the reviews aligned funding with the administration's public-health goals, while critics warned the approach politicised biomedical science and threatened patient safety.

Research advocates said the outcome could reshape how billions of dollars in federal science funding are allocated. The Association of American Universities warned that continued uncertainty risked driving scientists abroad and slowing progress on cancer, Alzheimer's and infectious-disease research.