The national League of Conservation Voters is going after Colorado Sen. Cory Gardner over the embattled EPA Secretary Scott Pruitt.

Gardner and Sen. Dean Heller, a fellow Republican from Nevada, are targets of $257,000 worth of TV and digital ads urging them to oust Pruitt, the former Oklahoma attorney general and climate change doubter who has fallen into a dozen ethics complaints as head of the U.S. Environmental Protection Agency.

The ads are running in both English and Spanish.

Gardner’s office passed on commenting on the ads.

It’s worth noting that others have applauded Gardner’s work on environmental and public lands issues. Last year, for instance, the Outdoor Industry Association named him a Friend of the Outdoor Industry, and in 2014 President Obama signed the Outdoor Recreation Jobs and Economic Impact Act that Gardner introduced.

He also defended southwest Colorado’s Canyons of the Ancients when the Trump administration was reviewing national monuments last year.

Gardner isn’t up for re-election until 2020. Heller is characterized as one of the most vulnerable Senate Republicans running for re-election this year.

In November Heller faces Democratic Congresswoman Jacky Rosen in an election that could help swing control of the Senate. Polls have them virtually tied.

“Instead of siding with Coloradans who want the EPA to protect our clean air and water, Scott Pruitt has relentlessly attacked our environment and way of life,” Maria Handley, acting executive director of Conservation Colorado, the state’s largest environmental organization, said in a statement. “Sen. Gardner should immediately call on Pruitt to resign and take the opportunity to stand up for Colorado values.”

Democratic U.S. Rep. Diana DeGette of Denver pressed Pruitt in a House committee on Thursday.

Sara Chieffo, vice president for government affairs, for the League of Conservation Voters, said about 200 members of Congress, Democrats and Republicans, have called for Pruitt to resign, but not Heller or Gardner.

The ads call for them to say something about the scandals involving Pruitt.

“Heller and Gardner already stood by Pruitt as he sold out our families’ health to polluters by dismantling dozens of protections for our clean air and water, but their continued silence as Pruitt is engulfed in scandal after scandal shows just how deep their ties to corporate polluters go,” she stated.

The League of Conservation Voters are running Instagram ads in Washington, D.C. and Oklahoma urging him to resign.