President Trump’s nominee to head the Environmental Protection Agency’s watchdog office moved closer to confirmation Wednesday with approval from a Senate panel, raising questions about what might happen to the acting inspector general’s investigation into agency chief of staff Ryan Jackson.

Sean O’Donnell, Trump’s nominee to be the EPA’s new inspector general, advanced from the Senate Environment and Public Works Committee through a unanimous voice vote. Top senators on the panel said speeding his full confirmation could help resolve mounting tensions over Jackson’s actions.