Nine U.S. senators from states that have oil refineries sent a letter to President Donald Trump on Thursday urging changes to the country’s biofuels policy and asking for a meeting to discuss the issue. The letter reflects growing tensions between refiners that oppose the U.S. Renewable Fuel Standard - a law requiring them to blend increasing amounts of ethanol into the nation’s fuel each year - and the Midwest corn lobby that supports it.The Trump administration bowed to rising pressure from Midwest lawmakers last week, assuring them in letters and phone calls that it would ditch proposals, supported by the refining industry, to overhaul the biofuels policy.The senators said that decision could cost jobs.“If your administration does not make adjustments or reforms on matters related to the Renewable Fuel Standard, it will result in a loss of jobs around the country, particularly in our states,” according to the letter, which was signed by Texas Senator Ted Cruz, Oklahoma Senator Jim Inhofe, Pennsylvania Senator Pat Toomey and six others.