More than 100 lawmakers are calling on Environmental Protection Agency chief Gina McCarthy to reduce the amount of ethanol that oil refiners must blend into gasoline next year.

Signed by 169 House members, the letter sent to McCarthy on Thursday urged the EPA to lower the renewable fuel standard (RFS), arguing the current mandate is unrealistic.

“Whether it’s increasing amounts of ethanol in fuel or higher food and feed prices, the RFS continues to negatively impact American consumers and the economy,” Rep. Bob Goodlatte (R-Va.) said in a statement.

“The demands of the current RFS are unrealistic and are causing great uncertainty. As the blendwall approaches, it is clear that this flawed policy is not working,” Goodlatte said.

“The growing support from Members of Congress from across the nation and a diverse coalition of outside groups makes it clear that we must consider real legislative reforms to this mandate. In the meantime, I urge Administrator McCarthy to take immediate action to provide much needed relief from the RFS.”

Earlier this year, Goodlatte introduced legislation to completely revoke the renewable fuel standard. He spearheaded the letter to the EPA.