Sen. Susan Collins (R-ME) announced she would vote “no” on the confirmation of EPA administrator-designate Scott Pruitt.

Collins told Maine Public Radio on Wednesday that while Pruitt, currently Oklahoma’s attorney general, was “an accomplished attorney,” she had concerns about his record of suing the agency he has been tapped to lead.

“Specifically, I have significant concerns that Mr. Pruitt has actively opposed and sued the EPA on numerous issues that are of great importance to the state of Maine, including mercury controls for coal-fired power plants and efforts to reduce cross-state air pollution and greenhouse gas emissions,” she said. “His actions leave me with considerable doubts about whether his vision for the EPA is consistent with the agency’s critical mission to protect human health and the environment.”

Collins currently appears to be the only Republican planning to vote against Pruitt. Both of the Senate’s independents, Sens. Bernie Sanders (I-VT) and Angus King (I-ME), will vote against his confirmation, as will nearly all Senate Democrats.

Sen. Joe Manchin (D-WV) has spoken positively about Pruitt, saying in January that Pruitt “has the right experience for the position.”