Republicans are aiming to move a slate of Environmental Protection Agency (EPA) nominees next week after a dispute over the names this week.
The Environment and Public Works Committee was due to vote on six nominees, including four for the EPA, on Wednesday, but leadership delayed the hearing on Tuesday night.
The reason for the delay seems to be a dispute over the Trump administration's support for the Renewable Fuel Standard
A key lawmaker in that fight is Sen. Joni Ernst (R-Iowa), who sits on the EPW Committee.
Because Republicans hold only a one-vote majority on the panel, they need everyone to support a nominee to bring it to the floor. But Ernst has been especially critical of Wehrum, and the EPA's approach to ethanol generally. She was one of several corn-state lawmakers to meet with Pruitt on Tuesday.
On Wednesday, she said discussions over the RFS and the nomination are ongoing.
"Holding the EPA's feet to the fire has put us on a path to receive strong reassurances on biofuel volumes and the EPA's commitment to follow both the letter and the spirit of the RFS, as well as a commitment to not pursue other policies harmful to our farmers across Iowa," Ernst said in a statement.
"My staff and I will continue to keep a watchful eye as these assurances come to life, and while we are still in negotiations, I do feel good about the direction we are headed."
EPA Chairman John Barrasso (R-Wyo.) said a vote on the nominees is "likely next week."
"We'll let each senator speak for themselves," he told reporters. "We want to move all of the nominees together, so there were concerns