Image caption Strawberry picking is largely done by seasonal migrant workers

Recruitment agencies are warning that they cannot secure the number of workers needed by British farmers to pick their fruit and vegetables.

Over half of recruitment companies could not find the labour even in the "quiet" first months of this year.

The figure has been released by the Association of Labour Providers.

A survey by the National Farmers Union shows that last year there was a 12.5% shortfall of seasonal workers required to work on horticulture farms.

This led to some valuable produce being left to rot in the fields.

The strawberry-picking robots doing a job humans won't

Image caption The horticulture sector needs 80,000 seasonal workers a year

A total of 99% of seasonal workers on British farms come from Eastern Europe. Two-thirds of these come from Romania and Bulgaria.

Kent-based AG Recruitment and Management works in Romania to supply labour for 80 growers across the UK.

Over the next few months it needs to find 4,000 people to pick strawberries, raspberries, and eventually apples and pears. The agency is nowhere near that target, and is having to call farmers to say it will not have enough pickers for them.

According to co-director, Estera Amesz, the numbers of people wanting to work in Britain fell sharply after Brexit. A key issue was the fall in the value of the pound. She says it is also down to the uncertainty; people aren't sure what documents they now need.

"We used to have queues outside our office in Bucharest. Thirty to 40 people would come a day. Now, on a good day, it's a handful. We used to take the crème de la crème. Now, we are scraping the barrel."

The firm runs criminal history checks and the candidates do dexterity tests, but Mrs Amesz says her company has had to widen the net. She says she now considers those that, "have two hands and two legs, and stand a 50% chance of making it".

Rather than people coming to the company offices, they now have to travel deep into the Romanian countryside to sell the idea of coming to work in the UK.

Image caption Georgetta Sandulescu grows her own strawberries and sells them by the roadside

At one presentation in the city of Barlad, close to the border with Moldova, 30 people turn up, but only five sign up.

Alina Stan, 31, decides to make the journey. She has come to the UK before to pick flowers and fruit. With the money, she's building a house for her and her family. But as soon as she can, she'll stop coming. She says: "We hope in the next two years to be able to finish our home. But leaving my children behind is very difficult."

Image caption Alina will journey almost 3,000km to work picking fruit at a farm in Birmingham

According to Doug Amesz, Estera Amesz' husband and business partner: "We need an incentive. Previously we were looking for people with some English, now we find it difficult to recruit anyone with English."

Romania is one of the poorest countries in Europe. It is one of the largest recipients of EU money.

However, almost 30 years after the Romanian Revolution of 1989 and the fall of the communist leader Nicolae Ceausescu, its economy is growing at 6.9%. That's a much faster rate compared to Britain's.

It's creating a newly wealthy middle class.

Image caption Geography student Puiu Jonut, says English people can pick their own fruit

In Iasi, Romania's second city, young people say they have no intention of picking fruit.

Puiu Jonut, 23, studies geography.

"The English pick and choose what they want to do and leave the harder jobs for the foreigners," he told BBC News.

"There are a lot of English people that could work the fields and not let the fruit rot. That's why Brexit to me was really strange because the foreigners are coming to do the hard jobs and the low-paid jobs - surely you want them to stay."

Growers in Romania are also finding it tough to find pickers.

The director of the Research and Development Centre for Fruit Growing in Iasi, Gelu Corneanu, said: "It's really difficult to find workers to harvest our crops, mainly because they are attracted to other European countries.

"People tend to go and harvest garlic in Spain, then they harvest cherries in Romania and then they harvest strawberries in Greece."

Image caption Gelu Corneau says he struggles to find enough workers to pick his cherries

British farmers warned last year of the difficulties they were facing with recruitment, and according to the ALP report, three-quarters of agriculture and horticulture businesses anticipate shortages in low and unskilled roles in 2018.

Of these, over a quarter envisage a labour supply crisis. Some farmers have increased wages, bonuses, improved accommodation and other benefits to try to attract more foreign workers to come.

The government has pledged to address the issue of whether or not to introduce a scheme to give seasonal workers from further afield special permits to work in the UK, similar to the Seasonal Agricultural Workers Scheme (SAWS) that was closed in 2013. So far, no alternative has been proposed.

Image caption 90% of British farmers expect it to be harder to find seasonal labour this year

In a statement, the Department for Environment, Food and Rural Affairs, said: "Defra and the Home Office are working closely to ensure the labour needs of the agriculture sector are met once we leave the EU.

"We have been clear that up until December 2020, employers in the agricultural and food processing sectors will be free to recruit EU citizens to fill vacancies and those arriving to work will be able to stay in the UK afterwards."