Australia is set to suffer through an egg shortage for the next two months, as producers scramble to meet new free-range laws, with Melbourne and Sydney the worst-hit cities.

Supermarket shelves along the east coast that would usually stock eggs are bare, with many carrying large apology notices.

Australian egg consumption is up 3-4 per cent, which normally would be great news for farmers. But uncertainty around new free-range laws means the industry isn't willing to invest in new capacity to meet the demand.

In March, the federal government introduced a legal definition of "free-range", which limits producers to one chicken per square metre and requires chickens to have "meaningful and regular access" to the outdoors.