A strike at BHP’s Escondida and Spence copper mines in Chile entered a fifth day on May 31. Reuters reported that the union representing the workers was awaiting a decision by labor authorities over whether substitute workers the company called in are legal.

The 200-member union, which runs BHP’s Integrated Operations Center in Santiago, walked off the job as copper prices are spiking around the world. BHP responded to the strike by calling in substitute workers to keep the mines running, a move the union said violated their right to an effective strike.

BHP told Reuters in a brief statement that both Spence and Escondida “have adopted contingency plans to maintain its operation
“We are waiting for the audits in the DT (Labor Directorate) to address the issue of replacements,” said Jessica Orellana, president of the guild. She told Reuters that there had been no move to return to talks with BHP.

The walk-off marks the first by remote operations workers at the Escondida mine, testing the company’s resiliency to labor action in an era when more work is automated or off-site.

Workers for the union are considered contractors by BHP, which has raised questions about whether substitute workers can be hired to replace them during a strike. Chilean labor law in some cases forbids such replacements.

The strike at Escondida, the world’s largest copper mine, and at the smaller Spence comes as copper prices have spiked amid soaring demand as the world’s largest economies revive following more than a year of coronavirus-induced stagnation. The rising prices have given additional leverage to organized labor at Chile’s sprawling copper mines.

Since the start of the strike, BHP has not reported on the status of production at either of its operations.

The remote operations workers have held small protests in Santiago since walking off the job.

A separate union of workers at the Spence mine also rejected a contract offer by BHP late last week, and will enter a final round of government-mediated talks in a bid to stave off its own strike, union president Ronald Salcedo told Reuters.