LINCOLN, Neb. (AP) — Nebraska senators are pushing the Environmental Protection Agency to hold its support for renewable fuels when drafting rules that could limit amounts of ethanol blended with gasoline for fuel.

Forty-two of Nebraska’s 49 senators signed a letter sent to EPA administrator Gina McCarthy Thursday, urging her to consider the impact of modifying the market for the ethanol industry that contributes $5 billion annually to the state’s economy.

Supporters worry oil companies are lobbying to decrease the amounts of ethanol required in fuel under the Renewable Fuel Standard.

The letter says the Nebraska ethanol industry employs more than 1,300 workers and supports 3,300 other jobs.

The EPA is expected to release oil industry draft rules for 2016 on June 1.