The Treasury Department’s Dec. 19 decision sparked a backlash from Democratic lawmakers who are questioning the administration’s motives in lifting sanctions against three companies Deripaska controls: United Co. Rusal, En+ Group Plc and EuroSibEnergo JSC. Deripaska was once a client of President Donald Trump’s former campaign manager Paul Manafort and their work together has come under scrutiny as part of Special Counsel Bob Mueller’s probe.