Michael Race is a business reporter.

Farmer collecting eggImage source, Getty Images

Due to the length of time hens have been kept indoors, people can't buy free-range eggs in the UK.

Barn eggs will be labeled as such due to birds being kept inside for more than 16 weeks.

The country is experiencing its largest ever outbreak of bird flu and measures are in place to prevent it from spreading.

The majority of eggs produced in the UK are free-range.

It means they come from birds that enjoy unrestricted access during the day.

There will be signs in supermarkets to inform shoppers of the change.

The advice from the government was that there was still a high level of risk to birds of catching flu.

She said that this is an incredibly difficult time for all bird owners.

Ms Mahony said farmers were adapting hen houses to make birds more comfortable.

The H5N1 strain of bird flu began to increase in cases in November last year. The first case of the highly contagious virus was in North Yorkshire.

According to the National Health Service, it poses an extremely low risk to humans.

The government made it a legal requirement for all bird keepers in the UK to keep their birds indoors if they have pet birds, commercial flocks or just a few birds in a backyard flock.

Poultry grazing outsideImage source, Anthony Lee/Getty Images
Image caption, Avian flu is spread by close contact with an infected bird, whether it is dead or alive

Egg farmers have agrace period to maintain their free-range status, but this ended on Monday.

The government will not allow hens to go outside again until the risks to birds diminish.

The assistant director of food at the British Retail Consortium said shops and supermarkets would continue to support British farmers.

The government said it would work with farmers and retailers to implement branding changes.

We are experiencing our largest ever outbreak of avian flu and housing measures remain in force to protect poultry and other birds from this highly infectious and unpleasant disease.