A spectator eats strawberries and cream as she watches tennis at Wimbledon. (Carl Court/AFP/Getty Images)

It is a quintessentially British scene: watching the annual Wimbledon tournament while munching on British strawberries and cream.

But farmers here are warning that fruits and vegetables — including their beloved strawberries — could be left to rot in the fields this summer because Eastern Europeans are reluctant to work on British farms following the Brexit vote.

Britain’s immigration policy will be one of the central themes of the upcoming Brexit negotiations, which are expected to last up to two years. And many industries that rely on foreign labor — from construction to cleaning — are anxious about continued access to migrant workers after Britain leaves the European Union.

But the agricultural industry says it is already struggling with a worker deficit.

A recent survey by the National Farmers Union (NFU), an industry lobbying group, found that 47 percent of the companies that provide agricultural labor said they did not have enough workers to meet demand between June and September of last year.

Signs advertise pound sterling prices for peaches and strawberries on a fruit stall at Walthamstow market in London. (Chris Ratcliffe/Bloomberg)

Britain’s horticulture sector is hugely reliant on its 80,000 seasonal workforce, the vast majority of whom come from Eastern Europe. The industry is calling on the government to introduce temporary work visas for foreign workers from countries outside the E.U., such as Ukraine or Bosnia.

“Every strawberry at Wimbledon last year was picked by an Eastern European. If we don’t want shortages going forward, we need to get a new visa scheme sorted now,” said John Hardman, director of HOPS Labor Solutions, one of Britain’s largest recruiters of migrant farm labor.

Speaking from an airport in Romania, where he recruits many of the 12,000 seasonal workers his company helps to bring over from Eastern Europe, Hardman said that Britain is becoming a harder sell because of the devalued currency and perceptions of xenophobia.

After the vote last summer, there was a spike in anti-immigrant assaults, and recruiters say such reports spread quickly in migrant communities.

“It’s enough to have a few people that have bad experiences, and they put it on Facebook or Twitter, and it’s enough to push so many people away,” said Estera Amesz, co-founder of AG Recruitment, a British agency that brings in agricultural workers from the E.U. She said the firm’s Romania office has seen a 40 percent drop in the number of people inquiring about jobs on British farms over last year at this time.

Helen Whately, a British politician who chairs the all-party parliamentary group for fruit and vegetable farming, said during a recent parliamentary debate on the subject that Britain risks losing out on foreign labor because foreigners are “feeling a lot less welcome” and because of the weaker pound — it is about 11 percent down on the euro since the June 23 referendum.

“They do not have to come and work in the U.K.,” Whately said. “They are in demand across the whole European Union.”

Some say that more should be done to hire local workers, including increasing wages. But farmers say Britons cannot be enticed to pick plums and potatoes. Not only is the work tough and low-paying, but also the jobs are temporary, and moving from farm to farm is an unappealing lifestyle for those wanting to plant roots in a community.

Britain has previously offered temporary visas for seasonal agricultural workers, but it scrapped the program three years ago after Bulgarians and Romanians were given full access to the country’s labor market.

When asked whether the government would consider introducing a new work visa for seasonal agricultural work, the Home Office said in a statement that Britain “needs a fair and controlled immigration policy and that is exactly what this government will deliver.”

The statement continued: “We are determined to get the best deal for the U.K. in our negotiations to leave the E.U., not least for our world-leading food and farming industry which is a key part of our nation’s economic success.”

Andrea Leadsom, Britain’s environment secretary, recently suggested that the government will work with farmers to ensure there aren’t any shortfalls.

She told a farming conference in Oxford last week that access to labor was “very much an important part of our current discussions — and we’re committed to working with you to make sure you have the right people with the right skills.”

But she didn’t spell out any details. And farmers say that a solution needs to be found well before the negotiations that will precede Britain’s withdrawal from the E.U.

“We have had Polish staff who have been coming for a long time, some 18 years, but they are not sure if they will continue coming back next season,” said Ali Capper, who runs an apple and hops farm in England’s West Midlands.

Capper, who is also the head of NFU’s horticulture and potatoes board, said that European migrants want long-term certainty and that if they don’t come this year, “there’s a real possibility that we will have crops rotting in the field.”

Laurence Olins, chairman of British Summer Fruits, an industry association, said some farmers are already pushing the pause button on expansion and investments in new technology.

“People are now not planting apples because of worries over who will pick them,” he added.

Not all Eastern Europeans have been dissuaded. Daniela Dragomir, a 33-year-old from Romania who has worked on British farms for seven seasons, says she is keen to return to the U.K. “I like England. I like the system of English people,” she said.

But she said that friends are less enthusiastic and that some have deep concerns.

“Some people don’t want [to return] because of the impression that English people don’t want Romanians and Bulgarians to work for them.”

Chris Chinn, an asparagus grower whose farm employs up to 1,000 seasonal workers, said that his farm is recruiting staff for springtime picking and that “there is certainly a little bit more of a challenge to find the right people.”

“The government has so much to think about at the moment, and perhaps 80,000 seasonal workers isn’t at the top of the list,” he said. “But it has the potential to be catastrophic for our industry. If we don’t have staff, we can’t harvest those crops.”