Sen. Richard Blumenthal (D-Conn.) said it was “unacceptable” that General Motors (GM) still hasn’t given dealerships the replacement parts needed to fix faulty ignition switches.

“Having failed to deliver new ignition switches to dealers last week as promised, GM CEO Mary Barra says now they’ll be there as soon as possible,” Blumenthal said Tuesday. “That vague assurance is unacceptable when dangerously defective cars remain on the road and GM fails to provide adequate warning.”

GM has recalled several models of cars that have a faulty ignition switch that can cause the car to turn off while in use. The Department of Justice is investigating whether the auto manufacturer knew about the flaw before allowing the federal government to bail out the company.

Blumenthal has been critical of GM, accusing it of not doing enough to ensure drivers’ safety and pointing out that several people have died because of the defect.

“Saying that the new replacement parts will arrive soon is scant consolation to drivers whose cars fail in the meantime,” Blumenthal said. “I call on GM to immediately give dealers and drivers specific dates when all the necessary new parts will be available.”