On Shrove Tuesday, the biggest egg-buying day of the year, UK consumers are being warned that eggs branded as free range have actually been laid by housed hens because of emergency measures to combat the spread of bird flu.

All free-range egg boxes will carry a sticker explaining that the box contains “eggs laid by hens temporarily housed in barns for their welfare”.

But consumers, who will be stocking up on eggs to make pancakes on Tuesday, will still be charged a premium for free-range eggs.

The UK consumes an estimated 52m eggs on Pancake Day, more than double the normal rate. About half the eggs sold in supermarkets are usually free range.

On 6 December poultry farmers were ordered to house their flocks to protect the UK from a virulent outbreak of avian flu.

The stickers are being introduced because, under EU rules, if hens have been housed for more than 12 weeks they cannot be sold as free range.

Andrew Opie, the director of food policy at the British Retail Consortium, said: “What we will start to see is stickers appearing on boxes of eggs to indicate that the hens that have produced those eggs are no longer free range. The likelihood is that all egg boxes will be stickered.”

Asked by BBC Radio 4’s Farming Today programme whether prices would fall as a result, he said: “We would hope that customers would recognise that this is a challenge beyond the control of the farmers themselves and will continue to support British free range farmers through this difficult time.”

There have been several confirmed outbreaks of the H5N8 strain of avian flu this year, including on farms in Northumberland, Suffolk, Lancashire and Lincolnshire.

About 20% of egg producers have flocks in areas classed as a high risk of contagion. From Wednesday, the restrictions will begin to be eased.

All farmers in the high-risk areas will be required to continue to house birds. Those outside the area will be allowed to let birds out, but many are expected to continue to house their flocks as a precaution.

The UK consumes an estimated 52m eggs on Pancake Day. Photograph: Alamy

The H5N8 strain of bird flu poses no risk to humans. The British Free Range Egg Producers Association said birds were not being be kept in battery farm conditions.

It said: “While free-range egg farmers would prefer their birds to be outside, they also wouldn’t want to risk the health of their birds. Their sheds have plenty of room for the birds to move around freely and include scratching areas so birds can still display their natural instinctive behaviour.



“Farmers have also put in additional stimulants like footballs, cabbages and even Christmas trees to keep the birds happy.”

It added eggs “will still taste great and will have been laid by birds who were allowed outside before 6 December, and that will be allowed outside again as soon as it is safe”.

Opie said: “We expect more farmers to be bringing hens indoors than might be anticipated from those higher risk areas that have been identified by Defra [the Department for Environment, Food and Rural Affairs].

“That’s a genuine concern from farmers to prevent the virus entering their flocks and destroying their livelihood. We anticipate that all eggs will be stickered for that reason.”