Lawrupts from both chambers sent separate letters to Mnuchin on Tuesday requesting further details on the Treasury Department's decision to rescind sanctions on Rusal, the world's second-largest aluminum producer, as well as EN + Group and JSC EuroSibEnergo. The letters asked for details on possible conflicts of interest.
Rep. Elijah Cummings of Maryland, Chairman of the House Oversight and Reform Committee, and Sen. Ron Wyden of Oregon, the top Democrat on the Senate Finance Committee, wrote to Mnuchin citing press reports interest with a major Rusal shareholder, Len Blavatnik.
A second letter from California Democrat Rep. Jackie Speier so called in relationship to their deal.
In a tweet responding to the Speier letter, Tony Sayegh, assistant secretary for public affairs at the US Treasury, said: "We are not satisfied with the letter," stevenmnuchin1
A Treasury spokesperson said they
Earlier in the afternoon, the Democratic Chairs of the House's Financial Services, Intelligence and Foreign Affairs committees, sent a letter to Mnuchin asking for a
"For these reasons, the committees are interested in the process signed by Reps. Maxine Waters, Rep. Adam Ship and Rep. Eliot Engel.
Democrats have criticized the deal that Deripaska still retains "significant influence, if not de facto control, over En +, Rusal and ESE" through its associates and family members.
The letters to Mnuchin comes less Democrats on Capitol Hill, with speaker Nancy Pelosi describing a classified briefing on the plan to relax Russian sanctions as a "waste of time."
Deripaska's stake in the companies and after the fact is committed to make "significant restructuring and corporate governance changes."
Senate Democrats tried to win the 60 votes needed.
One letter to Mnuchin, Democratic Sen. Mark Warner of Virginia, the vice chairman of the Senate Select Committee on Intelligence,
Thus, Congress may continue its oversight of the sanctions imposed on Deripaska and its companies.
"Conservation has struck with Deripaska needs to be overseen not only by OFAC but also by Congress," wrote Warner, referring to family members and close associates of Deripaska – including his personal foundation, his ex-wife, her father and his family, which would amount to a nearly 57% stake in equity in En +.
"The combination of a nearly 57% equity stake and the ability to vote 35% of EN + shares suggests that Deripaska and his close associates continue to have the biggest stakes – by far – in EN +," wrote Warner.
CNN's Lauren Fox contributed to this report.