There are warnings of a risk of egg shortages in the run up to Christmas as farmers struggle with higher production costs and the impact of bird flu.

Photos of empty supermarket shelves have been circulating on social media, alongside reports online deliveries from retailers are also unable to fulfill orders with customers complaining eggs are proving hard to find in stores including Tesco, Asda and Sainsbury's.

On Monday, all poultry keepers were forced to bring flocks back indoors as part of efforts to control the UK's worst ever outbreak of avian flu that has seen hundreds of of thousands of birds lost to the disease since last year.

But alongside fighting the impact of the virus, which has recorded more than 100 new cases in just over a month, the British Free Range Egg Producers Association says the country's poultry farmers are struggling to work in the face of rising costs which are now crippling production.

The organisation, which represents more than 600 producers keeping around 16 million hens, says in March it asked for a 40p-per-dozen rise in egg prices and for the additional money to be passed along the chain to producers.

While egg prices have risen - by about 45p since the start of the year - alongside the price of many other foods, it claims the farmers supplying supermarket shelves are only getting around 5p to 10p of the increase.

A spokesman added: "Egg producers have been hit with huge hikes in production costs. Feeding hens is now at least 50% more expensive than it was, and energy prices have soared in the same way that consumers have seen their domestic bills rise. Spending on fuel has grown by 30%, while labour and packaging also costs more.

"Many of our members are losing money on every egg laid, and our data shows that even those who are making a small profit do not see a long-term future."

A recent survey by BFREPA of 163 free range producers in the UK revealed that 33% had either reduced their flock sizes and so were now producing fewer eggs, paused production temporarily or were preparing to leave the industry all together.

In a statement the organisation explained: "Fewer hens means fewer eggs and we warned in March that eggs could be in short supply by Christmas. Egg supply naturally tightens at this time of year as businesses and individuals prepare for Christmas, which may be exacerbating the situation. On top of this, avian influenza has resulted in the culling of laying hens too.

"We need to see farmers paid a sustainable price to restore confidence and optimism to the sector."