Farmers and food producers have warned that the effects of the Brexit vote are already being felt even before Britain has left the European Union.
The £112bn a year food industry warned that it will be "deeply affected by Brexit" and that it has already started to happen.
"It is clear that the effect of the decision to leave the EU is already being felt in the sector, as uncertainty and lack of clarity impacts business confidence," said a group of industry representatives in a letter to The Sunday Times.
Signed by the National Farmers Union (NFU), Food and Drink Federation and British Retail Consortium among more than 20 business groups, the letter called on the government to ensure frictionless trade, access to labour and "efficient and proportionate regulatory system".
"The government must be unqualified in its support for the UK’s food supply chain and the business of food production in post-Brexit Britain," they said.
It follows new data revealing that thousands of vacancies for work on fruit and veg farms across Britain remained unfilled last year.
A survey by the NFU and seen by the Guardian identified a shortfall of 4,300 workers, the first time since it was introduced in 2014 there were found not be enough, while the proportion of foreign workers returning also fell from 41 per cent in 2016 to 29 per cent in 2017.