WASHINGTON — The White House has dropped a proposed executive order that would have shifted control of National Institutes of Health research grants toward political appointees, Sen. Susan Collins said Wednesday. Collins, a Maine Republican who chairs the Senate Appropriations Committee, had urged the administration to abandon the plan after reports that it was considering a new board to oversee NIH grantmaking. The proposed board would have included White House budget director Russ Vought, who was expected to hold veto power over grant decisions. The plan also would have reduced the authority of NIH Director Jay Bhattacharya, who was slated to serve on the board. Its reported goal included cutting federal research funding to Harvard University, which has been a focus of the administration’s broader conflict with the institution. “We should not have a politicized process for awarding research and biomedical grants to institutions,” Collins said. “That needs to be merit-based.” The reported reversal comes after Congress signaled its opposition to an earlier proposal that would have placed political appointees in control of federal health grants. A stopgap spending bill approved this month included a provision, pushed by Collins, that temporarily prevents the administration from carrying out that earlier plan. The dispute has raised concerns about whether scientific research funding will be awarded through peer review and evidence-based standards or used to reward allies and punish institutions targeted by the administration. NIH grants support medical and biomedical research at universities, hospitals and other institutions nationwide. The administration’s efforts to restrict Harvard’s federal funding have already faced legal resistance. Last year, the White House attempted to block $2.6 billion in Harvard grants, but a federal court halted the move. The decision to abandon the proposed executive order was first reported by Semafor, according to the information released Wednesday. It represents a setback for efforts to expand political control over NIH funding and a temporary victory for supporters of an independent, merit-based research process.