A bipartisan group of 135 lawmakers signed a letter Wednesday asking the Environmental Protection Agency (EPA) to adjust a rule that requires corn ethanol production for transportation fuel.

The lawmakers want EPA Administrator Lisa Jackson to temporarily reduce the amount of corn ethanol that gets blended into gasoline under the renewable fuel standard (RFS). They say meeting this year’s target of 13.2 billion gallons of corn ethanol production will tighten corn supplies for livestock producers, given the widespread drought that has devastated farm production.

Reps. Bob Goodlatte (R-Va.), Steve Womack (R-Ark.) and Mike McIntyre (D-N.C.) are leading the effort. They will send the letter Thursday and hold a morning press conference to discuss the issue.