The Gibraltar copper-molybdenum mine is the second largest open-pit copper mine in Canada and the largest employer in the Cariboo region of British Columbia.

“Unifor has negotiated in good faith to avoid work stoppage at Taseko’s only functioning copper mine,” Unifor’s Western regional director Gavin McGarrigle said. “We need Taseko to get serious about resolving basic issues if we’re to avoid job action.”

Taseko has not responded to a request for comment.

Taseko posted its highest ever revenue of $525 million for 2023 in March, thanks mainly to the contribution of the Gibraltar mine, in which it held a majority 87.5% interest. The revenue represented a 34% increase from the year before.

In 2023, Gibraltar produced a total of 122.6 million pounds of copper, with an average copper recovery rate of 82.6% and head grade of 0.25%. This production was higher than the company’s original guidance and also 26% higher than in 2022.

Earlier this year, Taseko took full ownership of the Gibraltar mine after acquiring the remaining 12.5% stake from Dowa Metals & Mining and Furukawa.

Taseko’s shares were trading down 3.46% on Wednesday afternoon EDT. The company has a market cap of C$1.14 billion ($830 million).