A federal Minister, speaking in Port Pirie, slammed a company as "bed-wetters" for abandoning a Whyalla renewables project after pressure from the "green movement".
Resources Minister Senator Matt Canavan said Aurecon was as "weak as piss" and had failed to "stand up to a few hippies".
The company has withdrawn services from a solar farm at Whyalla after facing pressure over its involvement with the Adani coal-mining venture in Queensland.
Senator Canavan outlined the situation while speaking at the Global Maintenance Upper Spencer Gulf Conference and Trade Expo at the Northern Festival Centre.
Most of the 450 registered delegates were in the auditorium to hear his comments.
Senator listed four "weaknesses" in Australian resources development.
One of the problems was the activities of environmentalists who he described as "the bullies in the green movement". He said Aurecon had bowed to the movement's pressure.
"I will keep fighting for this industry. I will not let the bullies win," Senator Canavan said.
He said other "weaknesses" in resources were the lack of a major discovery of deposits, time-consuming approval processes and the need for energy supplies.
But he said last year Australia had exported a record $278 billion in resources.
Aurecon has been contacted for comment regarding the Minister's criticism. The company is a Melbourne-based engineering, design and advisory firm.
Another guest speaker, Premier Steven Marshall said the Upper Spencer Gulf was fundamental to the state's "transformation ambition".