The northern district president of the Construction, Forestry, Mining and Energy Union's mining division, Ian Murray, said yesterday that the union would reprise the tactics it used eight years ago in a highly publicised international campaign against Rio Tinto.

Mr Murray said Xstrata had built its Australian business with co-operation from the union but had "changed its spots" since becoming one of the Hunter's "big two" producers with Rio.

"Xstrata says they don't need 'third parties' involved in their industrial relations," Mr Murray said.

"If they get their way there is no question that safety will take a dive, wages and conditions will fall and profits will go up even further."

Mr Murray said the contracts were being used at the new Glendell open-cut near Singleton and he expected the company would also want to bypass the union at Mangoola (formerly Anvil Hill) open-cut near Denman.

Xstrata spokesman James Rickards confirmed the use of the non-union agreements.

"They have been successful in Queensland and other Xstrata operations and we prefer a direct relationship with our employees, which we believe is in the best interests of the business," Mr Rickards said.

Mr Murray said companies such as Xstrata and Telstra which is reportedly seeking savings of up to $50 million a year through a program including non-union agreements were "refusing to realise that Labor won the election". "WorkChoices is dead but these companies don't seem to have noticed," he said.

Mr Rickards said the union's "war rhetoric" was "excessive and ridiculously excitable", especially when Labor Prime Minister Kevin Rudd had endorsed the sort of contracts that Xstrata was using.

With coal prices booming and the labour market tight, Xstrata would be paying "excellent rates" at Glendell.