The complaint was lodged with the Australian National Contact Point, part of the Australian Foreign Investment Review Board.

The CFMEU said Xstrata contravened multiple Organisation for Economic Cooperation and Development guidelines.

“These principally concern numerous tactics to weaken or restrict collective bargaining, requiring or promoting individual employment contracts, failure to consult on major workplace restructuring including redundancies, and failure to actively redeploy workers made redundant,” the union said.

The union has further alleged that Xstrata breached other OECD guidelines through anti-competitive conduct with its major shareholder, Glencore International.

“Xstrata maintains marketing and other contractual relationships with Glencore that have not been competitively tendered, and which provide Glencore with a benefit that is not available to other shareholders in Xstrata,” CFMEU said.

“Other shareholders, including the CFMEU, are therefore materially disadvantaged relative to the major shareholder.”

While the OECD might consider the complaints, there are doubts over whether it can penalise any breaches of its guidelines.

More importantly, the union conceded to the Australian Financial Review that many of these claims concerning Xstrata’s coal mines in Australia did not breach the Fair Work Act.

An Xstrata Coal spokesman told the newspaper the company had denied the allegations and the complaint was part of an aggressive union campaign against Xstrata.