Biden administration officials will not finalize highly anticipated guidelines on new clean fuel production tax credits aimed at the airline and biofuel industries before they leave in January, three sources told Reuters,

Darling Ingredients (NYSE:DAR) -5.7% and Clean Energy Fuels (NASDAQ:CLNE) -4.6% on Tuesday following a Reuters report that the Biden administration will not finalize expected guidelines on new clean fuel production tax credits aimed at the airline and biofuel industries before it departs in January.

In response, groups are urging Congress to extend the credit, which they say helped the industry reduce carbon emissions.