Acting Environmental Protection Agency chief Andrew Wheeler’s past lobbying work is expected to draw scrutiny at his confirmation hearing for the permanent post.

A Senate committee on Wednesday will consider Wheeler as President Donald Trump’s nominee for EPA administrator. Wheeler has served as the agency’s acting head since Scott Pruitt resigned in July amid allegations over Pruitt’s spending and alleged favor-seeking.

Environmental groups want senators to question Wheeler about his lobbying for coal interests and others just before he joined the EPA.

The watchdog group Citizens for Responsibility and Ethics in Washington has filed an ethics complaint alleging Wheeler improperly oversaw regulatory rollbacks benefiting coal and others he had lobbied for.

EPA spokesman John Konkus calls that “baseless.” Konkus says Wheeler consults closely with ethics officials at the agency.