WASHINGTON — The U.S. Environmental Protection Agency (EPA) said it will complete a proposal to expand sales of higher ethanol blends of gasoline in time for summer, despite delays from the partial government shutdown.

“I still think we can get the rule done in time and what I mean by that is get the rule in place by start of the summertime,” Bill Wehrum, the agency’s assistant administrator for air and radiation, told reporters at a public event in Washington, referring to the name for gasoline containing 15% ethanol.

President Donald Trump had promised U.S. farmers and biofuels producers that his administration would lift a long-time ban on summertime E15 sales to help boost demand for the corn-based fuel.

“That was our original goal. I think we can still meet that goal,” Wehrum said, referring to finalizing the rule before June to get it in place for summer driving season.

The partial government shutdown had raised concerns the effort might not be completed in time for this year’s summer driving season, which begins in June, because agency workers were furloughed.

EPA workers are expected back to work soon after an apparent deal reached on Friday to end the shutdown.

The ban had been imposed over concerns that E15 contributes to smog in hot weather, though research has since shown that the 15 percent blend of fuel may not increase smog relative to the more common 10% blends that are sold year-round.

E15 has been a hot-button issue between the oil and corn industries. Farmers and biofuel producers have been lobbying for an end to the E15 ban to bolster demand, but the oil industry has expressed opposition to any policy that would further raise ethanol’s share of the fuel market.