The company, which refused to comment on production levels at the mine, has stated more than 6400 man hours had been lost to stoppages at Oaky North and that the operations would continue to use trained and competent personnel.

“The ongoing stoppages have created uncertainty among our workforce and the action is impacting their families,” it said.

ACTU secretary Sally McManus and Construction Forestry Mining and Energy Union leaders Michael O'Connor and Tony Maher joined striking workers from Oaky North for a rally in Tieri on Wednesday.

CFMEU president Tony Maher said Oaky North mineworkers had been on strike since May in response to Glencore's attempts to strip conditions from their Enterprise Agreement.

“Glencore wants to impose a whole raft of conditions on these workers that would reduce their pay, provide less security and increase their costs,” he said.

“This is just not on. These workers have been fighting this unfair agreement for two months and now it’s time for the rest of the country to join with them in taking a stand.”

McManus said Glencore was trying to force through changes to conditions that would reduce pay and make hours of work unpredictable.