Chickens and other captive birds will be allowed outside again from next week as the government confirms it is preparing to lift some of its most stringent bird flu restrictions.

Keepers were forced to bring their animals inside last November as part of efforts to contain the UK's biggest ever outbreak of avian flu which has seen more than 100 cases confirmed since the end of last year.

The extensive mandatory housing measures also meant free range eggs ceased to be available on supermarket shelves and had to be labelled barn eggs because hens were having to be kept inside.

But the Department for Food, Environment and Rural Affairs says from next Monday the animals can once again be returned to their outside spaces unless they are in an area which remains within a protection zone.

Those who intend to let their flocks go outside again are now being advised to spend the next few days preparing their outdoor spaces for the release of the birds and this should include cleaning and disinfecting all hard surfaces, fencing off ponds or any standing water and reintroducing wild bird deterrents that include ensuring food and water left out for kept animals cannot be taken by other wild birds.

With migratory wild birds most responsible for transmitting the virus bird keepers are being asked to continue applying enhanced bio-security measures to prevent the risk of future outbreaks.

The current Avian Influenza Prevention Zone will remain in force across the UK, with only the housing measures component of the current restrictions being lifted from Monday.

This means all bird keepers (whether they have pet birds, a commercial sized or a backyard flock) must still be diligent with cleaning and disinfecting equipment, clothing and vehicles, limiting access to their sites and making sure workers change clothing and footwear before and after entering all bird enclosures.

Those with chickens or other captive birds are also being asked to remain vigilant for any signs of disease both before and after restrictions are lifted at 00.01 on Monday, May 2, and report any problems to officials.

In a joint statement, the UK's four Chief Veterinary Officers said: "Whilst the lifting of the mandatory housing measures will be welcome news to bird keepers, scrupulous biosecurity remains the most critical form of defence to help keep your birds safe.

"It is thanks to the hard work of all bird keepers and vets, who have played their part in keeping flocks safe this winter, that we are in a position to take this action.

"However, the recent cases of avian influenza show that it’s vital that bird keepers remain vigilant for signs of disease and maintain stringent standards of biosecurity."