More than 100 jobs are set to be cut at mining operations on the Eyre Peninsula, linked to GFG Alliance.
It is the latest round of redundancies connected to the Whyalla steelworks, which says affected staff are now being consulted.
The mines in the Middle Back Ranges on Eyre Peninsula help feed Whyalla's steelworks — but as changes begin to be implemented to the type of iron ore being extracted, fewer workers are required.
Eddie Hughes says he is concerned about the lack of certainty for people working on mining and steelworks projects in the region. (Supplied: ALP)
"Any job losses, especially job losses of this magnitude, has a bad impact on your community," local Labor MP Eddie Hughes said.
"You're stripping away a lot of income and then those families — what are they going to do — are they going to look for work elsewhere?"
Mine owner, GFG Alliance said it was entering the next planned phase of its hematite iron ore ramp down as it shifts its focus to mining magnetite ore in the future.
It said up to 116 jobs will be shed by contractors, Golding and SRG from mid-October.
"Most of the employees that we speak to … and our members … are very disappointed in the situation and are very concerned about the ongoing future in Whyalla with the steelworks and the mine site," Australian Workers' Union Acting Secretary Gary Henderson said.
AWU acting state secretary, Gary Henderson. (Supplied: Australian Workers Union)
It come after an earlier wave of job cuts at the mine in May when 56 positions were dropped, and after 48 "white collar" jobs were axed at the steelworks last month.
Mr Hughes said he was concerned about how the business was being run.
"We need real certainty — we're just over all of the announcements, we're over the kicking the can down the road — this community deserves their certainty," he said.
The steelworks's furnace was offline for nearly four months earlier this year after it cooled too much following maintenance.
In a statement, a spokesperson for GFG Alliance said the company's mining contractor Golding had completed the first stage of its ramp-down process earlier this year.
"GFG's South Australian mining business has been liaising with its major contractor partners to plan and prepare for the transition to a greener future and magnetite ore mining with the required ramping down of its hematite mine where the hematite reserve is nearing depletion following 120 years of mining," the spokesperson said.
GFG says it plans to transition to magnetite ore mining as hematite resources are exhausted. (Supplied: GFG Alliance)
"We are now entering the next planned stage of this process with affected team members engaged in ongoing consultation in line with their EA."
The spokesperson said the changes would continue "over the coming months".
"GFG Alliance is moving forward on its journey to be carbon neutral by 2030 with a focus on mining the alternative and vast reserves of magnetite, the 'best of the best' raw material for the production of green steel and iron."
The company said it has invested over a billion dollars into the Whyalla operations since taking control of the plant in 2017.