The British Retail Consortium (BRC) has urged the government to secure a Brexit deal that avoids rocketing prices for consumers.
Writing to Liam Fox, the secretary of state for international trade, the BRC said that the retail industry, as the UK's biggest importer, needs tariffs and import costs to remain low.
BRC's chairman Richard Baker said: "We will be supporting the government through this complex and difficult process, helping them analyse how increased cost pressures on retailers could mean higher shop prices and identifying any opportunities for new trade deals that could benefit individuals and families."
The recent fall in the pound has been compounding problems for retailers; Sports Direct said on Friday that the flash crash in the pound resulted in a £15m hit to its bottom line because of the flash crash which wiped six per cent off the value of sterling in a matter of minutes
The BRC said retailers have been avoiding passing on cost pressures to consumers, but if the UK's tariff rates increased, retailers may have no choice but to make customers pay.
"Failure to strike a good Brexit deal by 2019 would have a disproportionately severe impact on retailers and their customers, because if the UK fell back on to World Trade Organisation rules the new tariff rates that the UK would apply to imports from the EU would be highest for consumer staples like food and clothing," the BRC said.
At the BRC's annual retail dinner in September, Baker said he was also hoping EU workers would be able to live and work in the UK despite the Brexit vote.
There are 120,000 EU nationals working in UK retail, and the BRC said they "deserve reassurance that they will still be welcome here, whatever Brexit may bring."