"Significant disruption", particularly in the supply of fresh fruit and vegetables, will be seen if infrastructure is not in place when frictionless trade with the EU ends on 1 January 2021, the British Retail Consortium has warned.
Michael Gove, chancellor of the Duchy of Lancaster, yesterday confirmed that import checks would need to be introduced at the start of 2021, when the UK leaves the single market.
He told a Border Delivery Group event: "The UK will be outside the single market and outside the customs union, so we will have to be ready for the customs procedures and regulatory checks that will inevitably follow."
He added: "You have to accept we will need some friction. We will minimise it but it is an inevitability of our departure.
"I don't underestimate the fact that this is a significant change, but we have time now to make that change."
The change will mean customs declarations will need to be submitted and goods will be liable for checks to ensure regulatory and food safety standards are being met.
Without the necessary infrastructure up and running from day one, consumers in the UK will see significant disruption
Responding to the announcement Andrew Opie, the British Retail Consortium's director of food and sustainability, told the BBC: "Government will need to move fast if it intends to provide the necessary infrastructure to carry out full border controls on imported goods from January 2021.
"Without the necessary infrastructure up and running from day one, consumers in the UK will see significant disruption, particularly in the availability of fresh fruit and vegetables."