General Motors (GM) has confirmed 13 deaths linked with the defective ignition switches in Chevy, Saturn and Pontiac vehicles, but government safety officials are hinting the number will grow as more victims are now being reported from GM ignition switch lawsuits filed by families nationwide.

The Center for Auto Safety and Consumers Union have reportedly written to the National Highway Traffic Safety Administration (NHTSA) claiming the number of deaths is 303, far greater than what has been acknowledged by GM. The letter also complained that the agency has fallen short in performing its job by not requiring GM to order a recall much earlier.

GM is disputing the Center for Auto Safety’s assertion that all the deaths are part of the ignition problem. The company says 47 crashes can be linked to the ignition switch problems, but maintained that only 13 deaths are linked.

“Without rigorous analysis, it is pure speculation to attempt to draw any meaningful conclusions,” GM said in a statement. “In contrast, research is underway at GM and the investigation of the ignition switch recall and the impact of the defective switch is ongoing.”

The GM ignition switch problem can cause a car to shut off while driving and disabling the airbag system. In February, GM recalled nearly 800,000 vehicles sold in the United States. The recall has been expanded and now affects more than 2.5 million Chevy Cobalt, Chevrolet HHR, Pontiac G5, Pontiac Pursuit, Pontiac Solstice, Saturn Ion and Saturn Sky vehicles in the model years 2005-2010.

What worsened the situation was news that GM knew about the defect for as much as a decade before the recall. Yet engineers failed to take any actions to correct the problem or warn consumers. GM CEO Mary Barra claimed company leadership was not made aware of the problem until February.

More GM ignition switch lawsuits are being filed in state and federal courts throughout the country. There is a central theme of allegations in these lawsuits: that GM failed to act promptly to correct the ignition problems and concealed the problem as driver error.