URBANDALE, Iowa–Iowa Republican U.S. Senate candidate Joni Ernst said Monday she didn’t see a problem in going to a campaign fundraiser sponsored by groups that don’t want to see preference given to renewable fuels, which are prevalent in ethanol-rich Iowa’s rural communities.

Ernst is scheduled to attend the Wednesday fundraiser in Washington, D.C, that is sponsored by the political action committees for the American Petroleum Institute and Exxon Mobil.

Ernst said, “I don’t feel uncomfortable because they knew where I stand with the renewable fuels standard. I stand firmly behind that and my record in the Iowa state senate backs that up.”

The liberal group, Americans United for Change, began a radio ad this week in Des Moines criticizing Ernst for going to the fundraiser. The ad says, “Big oil is spending millions of dollars to put Iowa ethanol out of business and leave us more dependent on their foreign oil.”

The Obama administration has proposed reducing the required bio fuels blend, which has been universally opposed by both Democrats and Republicans in Iowa’s Congressional delegation.