The announcement was made by UK-based animal welfare group, Compassion in World Farming (CIWF).

When CIWF awarded Sainsbury's with a Good Egg Award in 2008, it was on the promise of this remarkable move planned for 2010, yet the supermarket chain has managed to bring this commitment forward by a whole year.

According to CIWF, Sainsbury's sells 1.6 million eggs every day, which is more than 600 million eggs a year. It is the first major retailer to withdraw all the whole eggs it sells from battery cages.

Rowen West-Henzell, Food Business Manager at CIWF said, "We are over the moon that Sainsbury's has gone cage-free almost a year ahead of the store's original 2010 commitment. The scale of this move is breathtaking, with a total of 2.3 million hens every year now living cage-free as a result.

"We have worked closely with the Sainsbury's team throughout this transition. What stands out is their dedicated hard work and a genuine commitment to continuously improving life for all farm animals in their supply chain. Let this be an example to the other 'big-four' UK supermarkets who have failed to match Sainsbury's on this issue."

Finbar Cartlidge, Sainsbury's egg buyer, says, "We are delighted that all Sainsbury's shoppers will now enjoy higher welfare eggs whilst the other major retailers still continue with over half their eggs coming from caged hens. We've worked hard with our producers to deliver a range that continues to offer our customer's great value for money, is 100 per cent British and is improving welfare standards of over half a million hens each week."