The Trump administration intends to ask Congress to allow E15, an ethanol-gas blend, to be sold at the pumps year-round, a U.S. official familiar with the matter told CBS News. 

The 15% ethanol blend is usually only available part of the year under a waiver from the Environmental Protection Agency as temperatures rise to help ease high gas prices. The administration plans to make the request when it submits a supplemental funding request to lawmakers, the official said.

Several requests on budget matters and non-budgetary matters were scheduled to be sent to the Hill on Wednesday. 

A lower 10% ethanol blend is sold all year, but the 15% blend is subject to waivers because gas with the higher ethanol content evaporates more quickly in hot weather and contributes to higher levels of air pollution or smog. For this reason, federal rules normally require switching back to more costly blends. 

The move to make E15 available year-round represents the White House's latest effort to tame gas prices that have risen because of the war with Iran. President Trump repeatedly said on the campaign trail that he supported making E15 available year-round.

It was unclear if the proposal would have the votes to pass. 

Lawmakers from corn-growing states and other proponents of E15 argue the blend gives drivers a cheaper option at the gas pump and creates rural jobs. 

E15 prices are generally about 25 cents per gallon lower than regular gas, according to the Renewable Fuels Association. The White House has said E15 can collectively over $20 billion in annual fuel costs.

The Trump administration in March this year temporarily lifted gasoline regulations with emergency fuel waivers to allow refiners and retailers to sell E15 gasoline during a period ahead of and during the summer driving season.