WASHINGTON (AP) -- The government "pulled no punches" in investigating 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 Chevrolet probe, which began after a test car caught fire in June, three weeks after a side-impact test.
The government still owns 26.5 percent of GM's shares.
"We pulled no punches" during the investigation, said David Strickland, who heads the National Highway Traffic Safety Administration. Then asked if the company got a pass from his agency, David Strickland replied, "Absolutely not."
But Ohio Rep. Jim Jordan, who led the hearing by the House Oversight and Government Reform subcommittee, said he found it "deeply troubling" that the agency waited until November to notify the public about the fire.
Strickland said he would have gone public immediately if there were an imminent safety risk. He said it would have been irresponsible to tell people that something was wrong with the Volt while experts looked into the cause of the fire.
In response, the committee chairman, Republican Darrell Issa, R-Calif., said, "I hear you, I don't believe you."
Republicans questioned whether the delay was to help broker new mileage standards, which were negotiated last year. Strickland insisted there was no connection and said he had not been pressured by anyone from the administration on the investigation.
After the first fire, two others occurred later related to separate safety tests, and the agency opened an official investigation on Nov. 25. That ended last week, with the government concluding that the Volt and other electric cars don't pose a greater fire risk than gasoline-powered cars. The agency and General Motors know of no fires in real-world crashes.
GM chairman and CEO Daniel F. Akerson said sarcastically that while the company designed the Volt to be a great car, "unfortunately, there is one thing we did not engineer. Although we loaded the Volt with state-of-the-art safety features, we did not engineer the Volt to be a political punching bag. And that, sadly, is what the Volt has become.
"For all of the loose talk about fires, we are here today because tests by regulators resulted in battery fires under lab conditions that no driver would experience in the real world."
But the Republicans' aim was on the safety agency, as Issa told Strickland, "You guys screwed up by keeping a secret."
Some Democrats came to the administration's defense.
"I don't believe this hearing is about safety," said Rep. Elijah Cummings, D-Md. Instead, he argued, it was part of an attack on the Obama administration's support for GM and the electric car industry.
At first, GM blamed NHTSA for the June fire, saying it should have drained the battery to prevent any fires after the test. But the company quickly retreated and said it never told NHTSA to drain the battery. GM executives also said there was no formal procedure in place to drain batteries after crashes involving owners.
Now the company sends out a team to drain the batteries after being notified of a crash by its OnStar safety system.
The Volt has a T-shaped, 400 pound battery pack that can power the car for about 35 miles. After that, a small gasoline generator kicks in to run the electric motor. The car has a base price of about $40,000.