Senators Amy Klobuchar (D-MN) and Chuck Grassley (R-IA), in an August 2 letter to Attorney General Eric Holder and Federal Trade Commission Chairman Edith Ramirez, asked the agencies to investigate anticompetitive activity restricting the sale of renewable fuel. Specifically, the senators said they have heard allegations that the oil industry, known to be in opposition of the Renewable Fuel Standard, has been undermining efforts to distribute renewable fuels.