Farmers are warning of a Christmas turkey shortage because visa changes to allow labour recruitment from abroad have come too late.
A poultry association said big producers have already scaled back because they assumed they would not have enough staff to process birds.
And turkey farmer Paul Kelly told the BBC the damage had already been done.
The government has announced a visa scheme to allow 5,500 poultry workers into the UK on three-month contracts.
As part of the changes, 5,000 HGV drivers will be allowed into the UK on similar contracts in an attempt to keep supermarket shelves stocked and petrol stations supplied with fuel.
Kate Martin, chairwoman of the Traditional Farm Fresh Turkey Association, said: "This year it's looking like there is a national shortage of turkeys when we're talking about supermarket shelves, rather than buying direct from your farm.
"It is the supermarket shelves that will be emptier of turkeys this year than they have been before, only because there have been less turkeys placed on the ground; only because the big processers know that they will not get them processed."
She said some members of her association had already seen a rise in orders, with one reportedly seeing a 400% increase on last year.
Ms Martin said farms "are now missing a whole host of their workforce that they have been training and investing in over the last however many years. Those workers are no longer available for us to use on a seasonal basis - they will go find work in mainland Europe instead."
Paul Kelly, who runs the KellyBronze farm, said the major producers were resigned to producing fewer birds for Christmas.
"The damage has already been done for the bigger processors because they have not put the turkeys on the farm," he said.
Smaller producers, however, might be better prepared as they tended to recruit local labour rather than draft in large numbers of migrant staff, he added.
One supermarket group told the BBC it was far too early to speculate about Christmas stocks.
The British Poultry Council has estimated there are nearly 7,000 vacancies across the sector, leading some chicken producers to cut their output, and sparking shortages at restaurant chains Nando's and KFC.
Mr Kelly said: "There are chickens being killed on farms at the moment. There are pigs being shot in fields, because there are not enough people there to do the jobs."
A temporary visa scheme "is definitely not an answer" for the long term, he added.
Transport Secretary Grant Shapps said the package of visa measures would help the food and haulage industries cope in the run-up to Christmas.
"After a very difficult 18 months, I know how important this Christmas is for all of us and that's why we're taking these steps at the earliest opportunity to ensure preparations remain on track."
However, some business leaders said the measures did not go far enough, with the British Chambers of Commerce saying they were the equivalent of "throwing a thimble of water on a bonfire".