Supermarkets would be plagued by empty shelves and higher food prices in the event of a no-deal Brexit, grocery retailers have warned.

Major retailers including Sainsburys, Morrisons, Marks & Spencer and Lidl have all signed a letter from the British Retail Consortium cautioning of the impact of a no-deal scenario.

The BRC warned that stockpiling fresh food is impossible and reverting to World Trade Organisation tariffs would lead to higher prices, both for retailers and for customers.

The letter warns that only 10% of UK food imports are currently subject to WTO rules, and said a no deal Brexit would “greatly increase import costs that would in turn put upward pressure on food prices”.

It also points out that the UK is reliant on the EU for fresh produce such as lettuces, tomatoes and soft fruits, particularly in March when such produce is out of season in the UK.

The BRC uses the government’s own estimate that freight through Calais may fall by 87% from current levels. In this event, “the availability and shelf life of many products” will be reduced for consumers, it said.

To mitigate this, the UK could set import tariffs at zero but “that would have a devastating impact on our own farmers, a key part of our supply chains”, the BRC warned.

The letter, which carries the signatures the chief executives of 12 of the UK’s largest grocers and food retailers, has been sent ahead of a crucial vote in Parliament tomorrow, when MPs will have their say on Theresa May’s amended Brexit deal.