A group of more than 3,000 scientists is using the indictment of of Paul Manafort, the Trump campaign’s former chairman, to urge lawmakers to reject President Trump’s nominee to be the Agriculture Department’s top scientist by highlighting his ties to Russia.

The Union of Concerned Scientists released a letter sent to the Senate Agriculture, Nutrition and Forestry Committee on Tuesday signed by 3,100 scientists by opposing Sam Clovis as lead scientist.