The SPCA says retailers should follow the example of a leading British supermarket and set deadlines for stopping the sale of eggs from birds kept in cages.

Customer concerns have prompted the Sainsbury's chain to pledge to stop selling such eggs by 2012. Other British supermarkets have already stopped selling them.

Egg Producers Federation executive director Michael Brooks says Britain is a unique example, in that it is the biggest market in the world for free-range eggs.

He says supermarkets and other buyers in New Zealand will respond to customer demand - and so will producers.

Despite the increasing demand for free-range, barn-laid and specialty eggs, Mr Brooks says battery eggs account for about 90% of all eggs sold in New Zealand.

Source: Radio New Zealand