Bosses of a north London deli popular with Harry Styles and Sir Paul McCartney have warned Brexit rules are a disaster for their business.
Panzer's delicatessen in St John’s Wood has lost 37 suppliers from the European Union since Britain left the single market in 2021.
Owner David Josephs fears more will quit after the UK introduces new border checks later this month.
"The government says there won't be any disruption. I guarantee there will be," he said.
"We already have some meat suppliers who are saying it's becoming debatable as to whether or not it's economically viable to supply the UK."
Mr Josephs’ 80-year-old Jewish deli sells products from almost 100 countries and supplies nearly 200 restaurants.
One Direction star Styles famously gifted Liam Gallagher £3,000 worth of sea bass from Panzer's in 2019.
North London residents Sir Paul and Yotam Ottolenghi are said to both be regulars, according to GQ.
Since January 31 EU exporters of chilled and frozen meats, fish, dairy products and some flowers have had to present health certificates, signed off by a vet or plant inspector.
Smaller British retailers have claimed the rules delay the arrival of goods by weeks.
They are now warning that the start of physical checks, along with higher charges, from April 30 will restrict the variety and freshness of fine artisan foods such as charcuterie, cheese, pasta and olive oil.
It could also cause further price rises.
The government says the new checks will help prevent diseases and pests entering the UK and will level the playing field for British exporters.
It will take a "pragmatic approach" and does not expect significant disruption to imports.
But there is still confusion over how frequent checks will be.
"The goods posing the highest biosecurity risk are being prioritised as we build up to full check rates and high levels of compliance," said a government spokesman.
It estimates its border rules will increase costs for importers collectively by £330million a year, and increase food inflation by just 0.2 per cent over three years.
Food inflation in Britain leapt to a 45-year high of 19.2 per cent in March 2023 due to surging energy costs, labour shortages and disruption to Ukrainian exports, but it fell to 4 per cent in March.
Andreas Georghiou, who imports from small producers in France, Italy, Spain and Greece for his fine foods and ingredients store in south west London, expects the worst.
"They're not geared up for doing certification, they're not geared up for having vets coming to visit, so they're just saying no," he said.
At a recent trade show in Florence, the April changes dominated the conversation, said Carlucci.
"Everybody was saying, what is the UK doing? It was sort of disbelief really."
