Supermarket chiefs and farmers' unions have warned the government that a "hard Brexit" would put UK food supplies at risk.
A consortium including Sainsbury's, Morrisons, Marks and Spencer and the National Farmers' Union said migrant labour and tariff-free access to the single market are vital for their industries.
In a letter to The Times, the group of 71 food businesses with a collective turnover of £92 billion argued that access to seasonal and permanent employees from overseas is "essential" to the food supply chain in the UK.
The group also called for assurances that EU citizens already working permanently in the UK would be allowed to remain.
The letter states: "For our sector maintaining tariff-free access to the EU single market is a vital priority. It is where 75% of our food exports go, so all our farming and food businesses wish to achieve this outcome.
"The sector needs access to EU and non-EU seasonal and permanent labour, alongside assurances that EU workers already working permanently in the UK are allowed to remain.
"This access to labour is essential as it underpins the UK food chain's timely delivery of high quality affordable food to consumers. We would urge that the UK Government seeks both these goals as the whole of society and the economy will benefit."
Prime Minister Theresa May indicated that curbing immigration was more important than remaining part of the single market when she gave an update on plans for Britain's departure in a speech to Conservatives in October.
However, European leaders have made clear their opposition to giving Britain concessions on freedom of movement if it wants to remain part of the trading bloc.
Earlier this week, European Council President Donald Tusk also insisted there would be no deal on expats until after the Article 50 process for exiting is formally triggered.