A no-deal Brexit threatens the UK's food security and will lead to higher prices and empty shelves in the short-term, retailers are warning.
McDonald's, Sainsbury's and Waitrose were among those saying today they were "extremely concerned" about disruptions in the food supply chain, given that nearly one-third of the food Britons eat comes from the EU.
The warning comes in a letter from the British Retail Consortium and is signed by several of the major food retailers.
It comes ahead of crucial votes in Parliament tomorrow.
The letter from the retailers, and seen by the BBC, says there will be "significant risks" to maintaining the choice, quality and shelf life of food.
"We are extremely concerned that our customers will be among the first to experience the realities of a no deal Brexit," the letter says.
The industry says that "this complex, 'just in time' supply chain will be significantly disrupted in the event of no deal," and that there will be pressure on food prices from higher transport costs, currency devaluation and tariffs.
The intervention comes ahead of a crucial day for May's Brexit deal tomorrow, with Parliament considering a number of amendments that could prevent Britain from leaving the EU without an agreement on future relations.
MPs will consider a series of amendments to Theresa May's plans that could shape the future direction of Brexit.
While it will not be MPs' final verdict on the deal, they will vote on the amendments and, if one is passed, it will illustrate what changes to the deal might be enough to get a modified version of the deal through Parliament.
Retailers have been reluctant to intervene in the Brexit debate but are doing so now as the UK's departure date from the EU approaches.