Germany's Lufthansa is airlifting fresh fruit and vegetables to the UK on Wednesday as firms seek to beat the lorry chaos at sea ports
The airline said it is carrying 80 tonnes of food from Frankfurt to Doncaster Sheffield Airport for grocers including Tesco and Sainsbury's.
Almost 3,000 lorries remain stuck in Kent despite moves to re-start cross-Channel access from Dover.
There are concerns that testing drivers for Covid could delay food supplies.
France shut its border with the UK on Sunday for 48 hours to stop the spread of a new variant of the coronavirus found in the UK.
"Lufthansa Cargo is currently examining whether additional special cargo flights can be offered during the next days. We are also checking if a regular flight might be possible," a spokeswoman told the BBC.
"This could be with a freighter, but we are also examining if we could use passenger aircraft for freight flights only," she added.
Lufthansa said the delivery, sent by freight firm Venus International Transport, was destined for Tesco, Sainbury's, the Co-op and Aldi.
Doncaster Sheffield Airport told the BBC that in January, the "planned increase" in the number of flights of perishable goods had risen from three a week to eight.
The airport will be handling 700 tonnes a week in food freight, up from 300 tonnes a week. However, the airport said the increase was due to companies wanting to mitigate anticipated Brexit congestion, rather than the current issues at Dover.
"We have seen a general increase in freight traffic in the period since the pandemic began in March by around 40% year-on-year," a spokeswoman said.
"We are currently experiencing a large volume of enquiries for flights as a result of border closures and we are handling additional flights, such as today's, where possible. Naturally, this is already a busy period for the air-freight sector as a result of Christmas and Covid."
Some firms have been chartering private aircraft to move goods such as food, textiles and livestock as the Port of Dover and the Eurotunnel closed.
French residents and nationals who can prove they have had a negative coronavirus test will be able to travel from Wednesday, and lorry drivers can do so after a rapid lateral flow Covid test.
The food imports will be flown from Frankfurt, a major food distribution centre in Europe that receives goods from food producers all over the continent including Spain, the Netherlands and France.
Although France has given the go-ahead for travel from the UK to resume, the International Road Transport Union warned that testing truck drivers will cause significant delays.
"We don't think testing will work. The backlog can't be cleared if the tests take 30 minutes per driver," said Raluca Marian, the union's general delegate to the EU.
Britain imports nearly half of its fresh vegetables and the majority of its fruit, both mainly from the EU.
Tesco and Sainsbury's warned earlier this week that if the port chaos continued, the UK could see shortages of lettuce and some citrus fruits - which are typically imported from Spain and Italy.
Tesco has introduced purchasing limits on some products including eggs, rice, soap and toilet roll. Customers are allowed to buy up to three of each item.
On Wednesday, Andrew Opie, director of food & sustainability at the British Retail Consortium, said that some shortages could worsen.
"It is essential that lorries get moving across the border as quickly as possible. Until the backlog is cleared and supply chains return to normal, we anticipate issues with the availability of some fresh goods," he said.
In the past, the UK has turned to other means when fresh produce has been under threat.
In 2018, thousands of iceberg lettuces were shipped from Los Angeles to the UK due to a summer heat wave increasing demand for salad, while the hotter weather made it difficult to actually grow lettuces.
Last year, Frankfurt Airport handled 2.09 million tonnes of cargo, according to Airports Council International.
German companies imported €11.1bn (£10bn) of fresh fruit and vegetables - equivalent to 19% of the combined imports of all European countries, latest data from the Netherlands' Center for the Promotion of Imports (CBI) shows.
The airport's cargo terminal has 12,000 sq m of temperature-controlled warehouses, including 2,000 sq m (21,530 sq ft) of cold storage.