U.S. defends its record in dealing with Volt fires

General Motors CEO Dan Akerson, center, flanked by GM staff , listens to opening statements by the House Regulatory Affairs, Stimulus Oversight and Government Spending subcommittee, on Capitol Hill in Washington, as it held a hearing on the safety of the all-electric car, the Chevy Volt.

WASHINGTON -- The government "pulled no punches" in its investigation of battery fires in the Volt, General Motors' prized electric car, the head of the federal auto safety agency told Congress on Wednesday.

At a combative House hearing, Republicans questioned whether the government's partial ownership in the automaker created a conflict of interest for the Obama Administration in the inquiry of the Chevrolet model, which began after a test car caught fire in June. The government still owns 26.5 percent of GM's shares.

David Strickland, who heads the National Highway Traffic Safety Administration, said the company "absolutely" did not get a pass from the agency.