ORLANDO, Fla. (Reuters) - The U.S. Department of Agriculture’s deputy secretary said on Wednesday he is “hopeful” the administration will complete its rule allowing year-round sales of a higher ethanol blend of gasoline by summer, but the government should use “discretionary enforcement” of the summertime ban if there is a delay.

FILE PHOTO: A gas pump selling E15, a gasoline with 15 percent of ethanol, is seen in Mason City, Iowa, United States, May 18, 2015. REUTERS/Jim Young/File Photo

“I see this as a fallback plan in the event we don’t make the deadline,” the deputy secretary, Stephen Censky, said at a biofuels conference in Florida.

The higher ethanol blend, known as E15, contains 15 percent ethanol versus the 10 percent found in most U.S. gasoline. It is currently banned for sale during the summer over concerns it contributes to smog in warm temperatures.

President Donald Trump announced in October he was directing the Environmental Protection Agency to allow year-round sales of E15, in a win for the powerful corn industry which supplies ethanol.

Although there are concerns that E15 contributes to smog in warm temperatures, recent studies have shown it may not perform much differently than E10 blends in that regard.

The Environmental Protection Agency has said it is confident that it can complete its rule allowing year-round E15 sales by this summer, but the recent partial government shutdown has raised concerns of a time squeeze because agency workers were furloughed for weeks.

Censky said at the conference that he blamed the potential for a delay to the E15 rule on the shutdown. If the rule is delayed, it would be up to the EPA to decide how to enforce the summer E15 ban, he said.

There has been bipartisan concern on Capitol Hill over the timing of the rule. Democrat Senator Richard Durbin, in a letter to the EPA’s acting administrator, Andrew Wheeler, warned that failure to complete the rule by summer would only add to the uncertainty of the agriculture community, which has already been hurt by U.S. trade tariffs.

“I urge you to publicly commit to completing this rule before June, and I urge you to outline the steps EPA will take to ensure the E15 rule will be finished by that time,” said Durbin, who is from the farm-intensive state of Illinois.

On Tuesday, Bill Wehrum, who is in charge of the EPA department tasked with preparing the E15 rule, told Reuters that the agency was moving in a “very expeditious” way in drafting the rule and that it was aiming for a 45-day public comment period after release.