Households have been warned not to stockpile food and toilet roll ahead of 1 January when the UK will stop trading under EU rules, BBC reports.
On Sunday, 13 December, the UK and the EU agreed to extend a deadline aimed at reaching a deal on post-Brexit trade.
The British retail consortium (BRC) said ongoing uncertainty made it harder for firms to prepare for the New Year.
But it said shops had plenty of supplies and shoppers must not buy more food than usual.
“Retailers are doing everything they can to prepare for all eventualities on 1 January, increasing the stock of tins, toilet rolls and other longer life products so there will be sufficient supply of essential products, said BRC chief executive Helen Dickinson.
“While no amount of preparation by retailers can entirely prevent disruption there is no need for the public to buy more food than usual as the main impact will be on imported fresh produce, such as fresh fruit and vegetables which cannot be stored for long periods by either retailers or consumers.
Supermarkets are now used to dealing with anxious shoppers.
During the first lockdown earlier this year to stop the spread of the coronavirus, grocers introduced limits on goods such as toilet roll, dried pasta and UHT milk after panic buying by Britons.
There are fears shoppers might think disruption at ports after 31 December could lead to shortages in shops as the UK transitions to new trading rules with the EU.
The UK and the EU have agreed to carry on trade talks past Sunday’s deadline.
In a joint statement, Prime Minister Boris Johnson and European commission President Ursula von der Leyen said it was responsible at this point to go the extra mile.
Ms Dickinson warned: “without a deal, the British public will face over £3bn in food tariffs and retailers would have no choice but to pass on some of these additional costs to their customers who would see higher prices filter through 2021.
Other business groups welcomed the extension to trade talks but also cautioned that it was imperative that the UK avoid a no-deal Brexit with the EU.