A fall in UK net migration is a 'major threat' to the logistics sector which is already struggling to recruit staff, says the Freight Transport Association (FTA).
In the 12-month period to June this year, net migration is estimated to have fallen by nearly a third to 230,000.
In this 12-month period, 572,000 people arrived in the UK, and 342,000 emigrated, the Office for National Statistics report showed.
It is the first time that a full year of data has been available since the UK voted to leave the EU last June.
James Hookham, deputy chief executive of the FTA, said: "These statistics have confirmed what our members are telling us - EU workers are beginning to leave the UK and head home.
"We have had reports of businesses losing 100 EU nationals a month, partly due to uncertainty about the future, alongside improved opportunities at home and the devaluation of the pound, making UK earnings worth less when converted to European currencies”.
“EU workers are critical to the success of Britain’s supply chain. There are 43,000 EU truck drivers working in the UK and an estimated 120,000 EU warehouse workers.
"They play a vital role in the successful running of warehouses, transportation hubs and freight deliveries - moving the goods UK industry and every consumer needs. Without the contribution of EU workers, where are staff for the logistics industry going to come from?
“The Government needs to act swiftly and decisively to address this issue.
"The mass departure of these workers is a major threat to the logistics and freight sectors. If it escalates, there’s a danger some firms may be left without enough staff to continue trading.
“These numbers are a reminder that we need urgent clarification about the future rights of EU citizens to remain living and working in the UK after Brexit.
"We know this matter is one of the three items in the Withdrawal Agreement being negotiated between the UK and the EU.
"This matter must be settled at the forthcoming European Summit on December 15, before highly valued foreign workers lose confidence in the UK and the abandon UK business in larger numbers”.