Treasury has said it had no role in terminating these pensions. But emails obtained by the Daily Caller through a FOIA request indicate that Geithner was the "driving force" behind the decision.
Republicans have since said the decision appears politically motivated, as the only pensions cut were those earned by non-union workers. Camp said in his letter to Ruemmler that these emails "raise questions about the full extent of Treasury's involvement in the decisions that ultimately picked winners and losers among Delphi's retirees."
"Due to the apparent unfairness of this outcome, and in keeping with the Administration's public commitment to transparency, it is imperative that your office make plain whether political concerns affected decision-making in this matter," he wrote.
Last week, a bipartisan group of members of the House and Senate asked House Oversight and Government Affairs Committee Chairman Darrell Issa (R-Calif.) and Senate Homeland Security Committee Chairman Joe Lieberman (I-Conn.) to investigate the Delphi decision.