Coronavirus ‘rule of six’ forces farmers to downsize turkeys for Christmas and ‘put them on crash diets’

He said: "We have to decide what size people want and you can't even tell me today what size that might be.

"We can play around with rations a bit, and we can slaughter them a week or 10 days earlier, so we can reduce the size to a certain extent."

While turkeys can range up to 20kg, most Brits traditionally go for a 6kg to 7kg bird which can feed around 10 people and still leave plenty for a Boxing Day buffet.

And even though PM Boris Johnson has hinted he will suspend the rule of six at Christmas so families can spend it together some farmers are still taking no chances.

Richard Griffiths, chief executive of the British Poultry Council, has even suggested the birds can take an early trip to the abattoir.

"Ordering early can help producers better plan their Christmas season," he said. "We could slaughter some birds early, so smaller, but they would have to be frozen."

Other producers are preparing to cut their turkeys up into smaller portion sizes than usual - with one farmer in Essex planning to trial 'half-turkeys', after successfully doing so with geese.

Rob Morton, of Morton's Traditional Taste in North Walsham, Norfolk, revealed he has also had to "adapt" this year.

Speaking to Norwich Evening News, he said: "A lot of turkey farmers hide their head in the sand and never like cutting their turkeys up.

"But that is where the market is, so we have to adapt to that or get left behind."

He added that he is anticipating customers may drop down from a 6kg to 7kg turkey to a 4.5kg turkey, so that they can still have the whole bird.

Meanwhile, James Graham, of Peele's Norfolk Black Turkeys, near Dereham, Norfolk, said he reduced the number of turkeys he hatched in March by ten per cent.

He said: "I had to make the decision in March when the initial lockdown came in we were just getting the eggs ready to put in the incubator.

"I decided then to cut my numbers a bit and downsize, pre-empting a leaner year. I have gone down 10 per cent, and I don't think I'll have a sell-out this year."

It remains to be seen whether turkeys will be cheaper in supermarkets this year in line with the potentially smaller birds.

The popularity of turkey has slumped from 22 million birds in 2003 to 14 million last year.

The British Poultry Council is now encouraging the public to "take what's available, even if it's a slightly larger bird" to support farmers and make the most of Christmas.