The supermarket giants are working with farmers as they scramble to deal with an egg shortage.
The NSW Farmers Group has issued a fresh warning of a shortage, which its egg committee chairman Bede Burke says is caused partly by a downturn in investment in egg production infrastructure due to the long running debate over the definition of free range.
A new standard for free range - requiring no more than one hen per square metre - was agreed upon by state and territory ministers at the end of March.
Colder weather, which reduces the number of eggs hens lay, is also playing a part.
"Adding to the current shortage has been the two year cloud of uncertainty on the definition of free range which put a halt to all new investment," Mr Burke said.
Both Coles and Woolworths say they are working with egg suppliers to secure supply, and while prices have so far remained steady they have not given an indication of the impact the shortage may have on future prices.
"Demand for eggs first increased in the lead up to Easter and continued with Orthodox Easter four weeks later," a Coles spokesman said.
"Consumption has since remained high, which is expected in the cooler months when people tend to eat more eggs."
A Woolworths spokesman said all major food retailers were experiencing a shortage, particularly in free range.
"This has been driven by recent changes regarding the definition of free range and high demand during the long public holiday period at Easter," he said.
"During the year our preference is always to source from local suppliers where possible.
"However, we may source from other states in Australia to support stock levels if required."
Egg Farmers Australia spokesman John Coward said the shortage was "massive" because of a five to 10 per cent reduction in egg production during this year's winter months, combined with a four per cent increase in demand.
"People are starting to recognise the value of eggs as a form of protein," he said.
"That's been adding to demand."
The shortage should end in September or October when the weather heats up and free range hens start laying more eggs, he said.
In the meantime, there might be a slight increase in prices, he said.
