There are fears the UK's worst avian flu outbreak could put Christmas turkey stocks at risk if the virus continues to spread rapidly among birds this winter.

The country is in the midst of its largest ever outbreak of bird flu with over 150 cases confirmed since late October last year, with cases only expected to rise in the coming months.

Strict prevention measures, which forced those with captive birds and poultry stocks to keep their birds inside for many months, were in place across most of last winter as cases among wild bird populations which are most likely to spread the virus to captive flocks continued to spread rapidly.

Despite a relaxation of some bio-security rules come the spring, just days ago the Department for Environment, Food & Rural Affairs was forced to introduce regional Avian Influenza Prevention Zones (AIPZ) for poultry and captive birds in Devon, Cornwall, Suffolk, Norfolk and parts of Somerset and Essex after a number of cases were identified.

But with wild birds seen as super spreaders of the virus and thousands of migratory birds soon expected to return to the UK for the winter, the industry is now braced for cases to fast increase.

Dr Christine Middlemiss, the UK’s Chief Veterinary Officer, said: "We are seeing a growing number of bird flu cases on commercial farms and in backyard birds across the country driven by high levels of disease within wild birds.

"Unfortunately we expect the number of cases to continue to rise over the coming months as migratory birds return to the UK, bringing with them further risk of disease that can spread into our kept flocks."

All poultry gatherings, including fairs, shows and markets, have been banned in an attempt to minimise flocks mixing and keepers continue to follow stringent cleaning routines to try and get ahead of the virus - but the NFU Poultry Board says if the virus was to get among turkey stocks it could cause 'holy carnage' this Christmas.

In an interview with Sky News, chairman of the NFU Poultry Board James Mottershead explained: "It is a risk."

He added: "If bird flu, for example, gets into turkeys that could cause holy carnage; that could cause real supply chain issues in the run-up to Christmas time. The realities of it are quite severe.

"I do know of some instances where seasonal turkey producers have been affected by this, so far, this year. If you have an outbreak on your farm and your farm is classed as an infected premises, it is serious - you could be out of production up for up to 12 months."

Defra is asking all bird keepers to keep a close watch on their animals for any signs of disease and to keep records of mortality, movement of poultry and any changes in production.

The risk to human health from the virus remains very low, say health officials however people should not touch or pick up any dead or sick birds they find and instead report them to the Defra helpline on 03459 33 55 77.