The SPCA is urging battery hen farmers to consider converting to barn housing for layer hens rather than changing to colony cages.
The Egg Producers Federation has announced the proposed change to colony cages is accepted by the industry but that it will cost $150m and take an estimated 18 years for industry to recoup.
The SPCA said the cost of converting from battery cages to a barn system was less than converting to a colony cage system and would deliver the cage-free eggs consumers wanted.
"Consumers are becoming far more conscious of where and how their food is produced and they don't want cages," SPCA national accreditation and marketing manager Juliette Banks said.
"With a steady annual increase in the free-range egg market it is clear consumers will not accept caged eggs in the future. For the industry to spend millions converting a system that consumers will reject seems pointless."