Several hundred refinery workers rallied Monday to urge President Trump to fix the Renewable Fuel Standard, saying the federal ethanol-blending rule is creating an unfair and onerous burden for the region's independent refiners.

In a driving rainstorm that became a metaphor for the storm that embattled refiners face in Washington, a bipartisan lineup of politicians, labor and business leaders called upon workers to pressure Trump to reconfigure the market for ethanol fuel credits, which they say has been hijacked by big oil interests and "Wall Street sharpies."

"The people gathered today represent the manufacturing jobs that President Trump and Congress talk so much about preserving," said Jeff Warmann, chief executive of Monroe Energy, which is owned by Delta Air Lines. "These are good jobs."

"This is manufacturing," said U.S. Rep. Patrick Meehan (R., Pa.). "You don't have to bring it back. It's here today. We just have to keep it."

The rally was organized by the Fueling American Jobs Coalition headed by the refiners, who have been fighting an uphill battle in Washington to rework the Renewable Fuel Standard. The RFS requires blending biofuel, principally ethanol, into motor fuels.

The coalition is trying to redefine its message so that it does not appear opposed to the RFS, which has strong legislative support in farming states, where most of the corn ethanol is produced. Rather, they want the administration to reconfigure who is responsible for shouldering the cost of biofuel credits called RINs, or Renewable Identification Numbers.

"This is not a fight against biofuels," said Warmann, who said Monroe Energy spends $500,000 a day for RINs, or more money per year than the $150 million Delta Air Lines spent in 2012 to buy the refinery.

The RFS program, established in the Energy Independence and Security Act of 2007, is administered by the Environmental Protection Agency to force the industry to blend ever-increasing volumes of biofuel like ethanol into motor fuel. Every gallon of ethanol that is blended into fuel generates a RIN, which is then sold to a producer or importer of gasoline.

Integrated refiners, who blend fuel and distribute it to their own retail outlets, generate their own ethanol credits. But merchant refiners, who sell fuel to blenders, need to buy RINs on the market to meet their obligations. The price of a RIN has escalated from a few pennies to more than a dollar.

Independent refiners — including Monroe Energy; Philadelphia Energy Solutions, which operates the South Philadelphia refinery complex; and PBF Energy, which owns refineries in Paulsboro and Delaware City, Del — say the soaring cost of the credits does not benefit producers of biofuel, but large oil companies and traders that control the unregulated RINs market.

"All it's doing is hurting the working men and women," said U.S. Rep. Bob Brady (D., Pa.), who spoke at the rally, along with U.S. Rep. Ryan Costello (R., Pa.). "It's just making the rich richer."

Supporters of the refiners suggest that the EPA could step in and rewrite the RFS rules to put caps on the price of RINs or other market controls.