Farmers are fearful of the impact of the vote to leave the EU, which has put European funding, access to migrant labour and crop values at risk.

Oliver Doubleday, chief executive of GH Dean in Tonge, near Sittingbourne, said the rural economy is facing uncertainty after the Brexit vote.

EU agricultural subsidies are set to disappear in the UK after the vote, which makes up a large part of farmers’ income.

The sector is also preparing for higher import costs on oil and fertiliser as the value of the pound continues to fall following the referendum result, although this should boost exports short-term.

There are also concerns about access to Eastern European pickers, who are vital during the harvest season.

Mr Doubleday said: “With the huge fluctuations in currency, I don’t know what anything I grow is worth today.

“Exports are worth more after the devaluation of the pound but how long that lasts, I don’t know. It may also affect my import costs.”

As part of the EU, farmers received subsidies under the Common Agricultural Policy, which will no longer be the case when Britian leaves.

Mr Doubleday said: “Although reassurances were given by various Brexiteers that grant support would continue from the Government outside the EU, farmers would be naive to think they would get preferential treatment if the economy goes bad.

“We are going to be part of all those departmental budgetary constraints but that’s a long way down the road.”

National Farmers Union president Meurig Raymond said the result would inevitably lead to a period of uncertainty.

“Unless labour can be recruited from abroad, many growers will be forced to cease production which will damage local businesses..." - Adrian Barlow, English Apples & Pears

The NFU has called an extraordinary meeting of NFU Council, its governing body, on Friday.

Mr Raymond: “We understand that the negotiations will take some time to deliver but it is vital that there is early commitment to ensure British farming is not disadvantaged.

"It is vital that British farming is profitable and remains competitive, it is the bedrock of the food industry – Britain’s largest manufacturing sector.”

Adrian Barlow, chief executive of English Apples & Pears, the UK growers’ association based in East Malling, said restrictions on migrant workers posed a “huge potential risk” to growers.

He said: “The UK apples and pears sector requires about 12,000 seasonal workers per annum.

“Unless they can be recruited from abroad, many growers will be forced to cease production which will damage local businesses, local economies, the national economy and prevent consumers from enjoying the finest tasting apples in the world.

“It is vital that the UK government takes into consideration the essential requirement for seasonal workers from abroad in order to allow the commercial production of apples and pears in the UK to continue, and that policies are implemented accordingly.”

Clive Stevens, executive chairman of accountancy Kreson Reeves, said: “There will be a lot of farmers wondering if there will be restrictions on overseas labour. A lot of the rural economy depends on pickers coming in from other countries.”

However, Mr Doubleday seemed calmer on the issue, saying: “Access to labour is a significant concern but it worked perfectly before the expansion of Europe.

“There were various mechanisms in place which brought Eastern European people prior to their accession to the EU.

“There’s a heck of a lot of uncertainty but people are sensible and hopefully we can come out of it without to large a hiccup.”