According to sources with knowledge of the situation, Chief of Staff John Kelly gave the greenlight to the efforts to remove the three officials after Pruitt’s resignation from the EPA this month. Kelly, along with other senior aides to President Donald Trump, campaigned for months for Pruitt’s firing. As The Daily Beast reported in early April, Kelly had a tense phone call with Pruitt, telling the now-former EPA chief that the torrent of scandals needed to stop.

At least one of the axed Pruitt aides, spokesman Lincoln Ferguson, had planned to leave the EPA prior to Pruitt’s departure. But the White House Presidential Personnel Office, overseen by senior Trump aide Johnny DeStefano, expedited his resignation.

Senior EPA communications adviser Jahan Wilcox, who frequently clashed with the press and served as a top enforcer for his chronically embattled former boss, was also asked to tender his resignation at PPO’s request. Hayley Ford, the EPA’s deputy White House liaison, was also pushed out this month following Pruitt’s ouster.