Unions say the Abbott government has run Holden's car making operations out of Australia and the outcome will affect tens of thousands of workers.
ACTU boss Dave Oliver lashed out at the federal government for failing to provide adequate support to the General Motors-owned car maker, which on Wednesday announced it would stop manufacturing in Australia in 2017.
Mr Oliver said it was a sad day for auto workers, for the industry and the country, and laid the blame at the feet of the new government.
"We have a government that has successfully run Holden out of town," Mr Oliver told reporters in Canberra.
"I guess we can say that the Treasurer today, who was on the front page of paper daring GM to leave, got his wish."
There would be a knock-on effect for tens of thousands of workers in the auto components industry, and Mr Oliver dismissed as a "furphy" government claims high labour costs had hurt the company.
"There would be plenty of those workers out there today that voted for (Prime Minister) Abbott asking themselves the question, `why didn't he do anything'," the ACTU secretary said.
The loss of Holden also put a "question mark" over the future of Toyota in Australia.
"I note that Toyota is seeking some engagement with the government," Mr Oliver said.
"One would imagine that if they're going to handle it the same way they're going to handle this, you would certainly say that Toyota will go."
