A brief peace between the Trump administration and US grain farmers was at risk after his environmental agency published the details of a biofuels policy they had broadly praised 11 days before.  The policy deals with exemptions small oil refineries may receive from a rule requiring set amounts of corn ethanol to be blended into petrol. In early October, the administration said it would compensate for any corn ethanol sales lost to the exemptions, winning cheers from the farm and ethanol lobbies. On Tuesday, the applause turned to dismay after the Environmental Protection Agency released more precise information in a 20-page notice. The lobbyists said it would not buttress ethanol as promised. The Iowa Corn Growers Association said it was “outraged”. Emily Skor, chief executive of ethanol group Growth Energy, said it was “unconscionable”. The proposal “falls short of delivering on President Trump’s pledge”, said Geoff Cooper, president of the Renewable Fuels Association.

About 40 percent of the US corn crop is processed into fuel ethanol, making the biofuels industry important to rural Midwestern states that are critical to President Donald Trump’s re-election chances in 2020. The number of biofuel exemptions granted to oil refineries has increased sharply under Mr Trump, angering farmers who believe the waivers undermine ethanol and biodiesel demand.EPA earlier said the agency would ensure that more than 15bn gallons of corn ethanol be blended into the US fuel supply in 2020, as required by statute.