The Tennessee General Assembly is working through a bill that would require refiners and major product suppliers to provide unblended gasoline and diesel fuel to the state in order for wholesalers in Tennessee to blend ethanol and biodiesel into the fuel, officials said.

The bill, sponsored in the state Senate by Sen. Jamie Woodson, the speaker pro tempore, passed April 16 with one dissenting vote, and is now working its way through the state House of Representatives.

The House Commerce Committee considers the measure this week with the bill now expected to be enacted into law by the end of May, said Lee Harrell, an aide to Woodson.

Oregon legislators are attempting to make changes to a law passed two years ago that mandated ethanol in the state in a way that will allow the sale of premium gasoline without an ethanol blend, while also mandating biodiesel.

In 2007, Oregon passed a Renewable Fuel Standard that mandated blending 10 percent of ethanol into all gasoline sold in the state. The law didn’t allow for any exceptions, with the state ushering in the mandate in three phases in 2008 on Jan. 15, April 15, and Sept. 16. The 10 percent mandate took effect in the city of Portland, which had been blending ethanol during the winter months for years under the Environmental Protection Agency’s State Winter Oxygenated Fuel Program, on Nov. 1, 2007.

However, opponents of ethanol have been trying hard to repeal the law. In recent months, local politicians allied with the ethanol opponents have mounted efforts to reign-in on the state’s RFS program though the legislature.