Australia's peak business group has called on state and territory governments and unions to abandon a High Court challenge to new industrial laws.
The court is set to begin hearing the challenge in May, which will claim several aspects of the laws are unconstitutional.
The Australian Chamber of Commerce and Industry says the challenge creates uncertainty for workers and bosses at a time when certainty is needed.
It says governments, unions and employers should instead start talks to put in place a truly national workplace relations system using Victoria's 1997 referral of powers as the basis.
But unions are standing by the challenge and claim workers are now voting with their feet against the new laws, by joining them in large numbers.