Mike Devereux, chairman of GM Holden, has refused to guarantee employment for Holden workers in exchange for government assistance.
Devereux mentioned such a guarantee would be "quite a difficult thing to do", after the federal opposition suggested that future support be linked to job protection.
"There are no guarantees in life,” he told News Limited. “I don't know how many cars Australians will buy in 2016.
“Our current agreement with the Federal Government does not include minimum employment levels. (The assistance) is designed to generate the capacity to build things … and jobs flow from that."
Holden announced on Monday that it would make 500 workers redundant in South Australia and Victoria, a week after it revealed that it had received nearly $2.2 billion worth of government assistance over the last 12 years.
Federal opposition industry spokeswoman Sophie Mirabella said any future funding for Holden should be tied to jobs.
"The South Australian Premier Jay Weatherill did a handshake deal to secure jobs (at Holden) for $50 million,” she said.
“What did the Federal Government ask for in return for a $215 million grant? There was obviously no commitment around the workforce."
Meanwhile, the Federation of Automotive Products Manufacturers stated that future job cuts for car parts makers were inevitable with Holden’s decision to scale down production.
"That's unclear at this stage but the reduction in volume will mean there will be some sort of employment effect on the supply chain," he told AAP, saying there would be a “straight flow-through” in demand for parts.