The “unnatural relationship” between the Obama administration and US carmakers in the wake of the 2009 auto bailouts may have led to a delay in disclosing a potential safety defect in Chevrolet Volts, Republican lawmakers claim in a House Oversight and Government Reform Committee report. Some Republicans questioned whether the US government’s 32-percent ownership stake in General Motors means that it cannot be “an effective regulator.”

Specifically, US Representative, Darrel Issa (R-CA), stated “This unnatural relationship has blurred the lines between the public and private sector as President Obama touts the survival of General Motors as one of the top accomplishments of his administration. On a policy level, this relationship raises serious questions about whether or not the administration is too heavily invested in the success of GM to be an effective regulator.”

Today’s hearing—titled “Volt Vehicle Fire: What did NHTSA know and when did they know it?”—stems from the Volt fire incidents and the National Highway Traffic Safety Administration’s (NHTSA) handling of the issue. Republicans assert that both General Motors and the NHTSA delayed disclosing info related to the first Volt fire until after Bloomberg News broke the story.

The NHTSA opened a formal investigation in late November and closed it in mid-January, concluding that “no discernible defect trend exists” and that “modifications recently developed by General Motors reduce the potential for battery intrusion resulting from side impacts.”

Meanwhile, General Motors denies that the US government’s ownership stake affects its operations. Greg Martin, a spokesman for GM, told Automotive News, “The administration’s been true to their word from the start and has not interfered in our business. As our actions with the Volt have demonstrated, we’ve always put our customers’ safety and peace of mind first, above all else.”

In testimony prepared for today’s hearing, General Motors CEO, Dan Akerson, stated “The Volt’s entry into the market came soon after GM’s emergence from its government rescue and restructuring—and during this political season. As such, the Volt seems, perhaps unfairly, to have become a surrogate for some to offer broader commentary on General Motors’ business prospects and Administration policy.”

Finally, NHTSA Administrator, David Strickland, will testify that the Agency took the “uncommon step” of opening a formal defect investigation despite the fact that no Chevy Volt fires were reported outside crash tests. Strickland says that the NHTSA’s decision to investigate the Volt was to “ensure the safety of the driving public with the emerging electric vehicle technology.”