Sens. Dianne Feinstein and Tom Coburn Thursday introduced legislation to eliminate the corn ethanol mandate in the Environmental Protection Agency's Renewable Fuel Standard, citing impacts on the cost of food and animal feed.

Feinstein, D-Calif., and Coburn, R-Okla., cited the blend wall and the policy's increasing corn consumption as reasons to eliminate the corn ethanol mandate, though they clarified that the bill would maintain provisions designed to grow the low-carbon biofuel industry.

Feinstein, Coburn offer up legislation to scrap corn ethanol mandate in Renewable Fuel Standard

"Under the corn ethanol mandate in the RFS, roughly 44% of U.S. corn is diverted from food to fuel, pushing up the cost of food and animal feed and damaging the environment," Feinstein said in a statement announcing the bill.

She also addressed the "blend wall" – a concern that the amount of ethanol produced will soon be too great to be absorbed into the fuels mix at a 10% blend.

"Oil companies are also unable to blend more corn ethanol into gasoline without causing problems for automobiles, boats and other vehicles," she added. "A corn ethanol mandate is simply bad policy."

The Renewable Fuel Standard, first enacted in 2005, requires refiners and blenders to use 16.55 billion gallons of renewable fuel in 2013. More than 13 billion gallons of this total will be met by the use of corn ethanol, the Senators said.

Coburn said eliminating the corn ethanol mandate would let the market operate naturally.

"Eliminating this mandate will let market forces, rather than political and parochial forces, determine how to diversify fuel supplies in an ever-changing marketplace," he noted in a statement.

Refiners will continue to blend corn ethanol into the fuel supply in the absence of a mandate, the Senators said, as ethanol is the preferred octane booster used to increase the efficiency of gasoline.

Even without a mandate for its use, the Senators argued that the economic benefits of mixing ethanol into gasoline would remain.

The bill comes amidst a proposal from the EPA to lower RFS requirements, igniting strong opinions from both sides of the discussion. The EPA is currently considering public comments on proposed changes.

Cosponsors of the bill – dubbed the Corn Ethanol Mandate Elimination Act of 2013 – are Richard Burr, R-N.C., Susan Collins, R-Maine, Bob Corker, R-Tenn., Kay Hagan, D-N.C., Jeff Flake, R-Ariz., Joe Manchin, D-W.Va., Jim Risch, R-Idaho and Patrick Toomey, R-Pa.