Around 200 workers of South32’s Dendrobium coal mine in Australia have gone on seven day strike from Friday after failing to reach workplace agreement.

Workers at Dendrobium mine represented by the Construction, Forestry, Mining and Energy Union (CFMEU) will cease the operation, which will halt the supply to BlueScope Steel’s Port Kembla works.

CFMEU Mining and Energy Division South West District vice president Bob Timbs said that the union had been attempting for the past 18-months to reach a new Enterprise Agreement.

"We sat down with the company again today and put forward some proposals designed to break the deadlock and we are very disappointed with their refusal to come to fair terms."

The CFMEU met with top-level management of the mine but the meeting was not fruitful as the management rejected the new job security clauses that were sought to be added to the workplace agreement.

Timbs added that contractors were supposed to be used to fill temporary gaps in the labour force, not to replace permanent full time jobs.

"The company appears to be entering into a strategy of replacing permanent full time employees with contractors when workers retire, resign or are promoted, meaning the permanent workforce is slowly but surely being casualised."

"Around 20 per cent of the workers employed at this mine are now contractors and that number is considerably higher at other South32 mines. It’s going to keep increasing unless we take a stand."