Mining unions have won a landmark legal victory that is set to allow them bargaining rights over pay and conditions at the booming Pilbara iron ore operations of Rio Tinto and BHP Billiton.


The Federal Court ruled that Rio Tinto’s non-union agreement over pay and condition was invalid, giving unions the right for collective bargaining.


The ruling has cast doubt over the validity of a similar non-union agreement that BHP Billiton has with its employees.


Although the collective 20,000 iron ore mining workforce of the two mining giants is largely un-unionised, the victory is set to give the mining unions a formal role in representing bargaining and conducting legalized industrial action.