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The federal government offers tax credits of as much as $7,500 for the Volt, and a handful of states offer additional incentives.

Those tax credits, along with the fact that several GM board members were appointed by the Obama administration, have helped the Volt become a symbol of the federal government’s and environmentalists’ desire for cleaner cars, Mr. Akerson said.

“We did not engineer the Volt to be a political punching bag,” he said. “Sadly, that is what it has become.”

As a result of the fire and subsequent investigation, Mr. Akerson said, GM has further encased the battery to prevent it from being punctured and at risk of exploding. Such an incident has not occurred outside laboratory tests, he said.