Members of the logistics industry are warning of "significant gaps" in UK border plans for the end of the Brexit transition period on 31 December.
Eight groups warned ministers that if issues were not addressed, the supply chain "will be severely disrupted".
The government said it had plans to ensure "we are ready for the changes".
Meanwhile, the government has given itself powers to build temporary lorry parks in parts of England, without the need for local approval.
In a letter to the Cabinet Office Minister Michael Gove, obtained by the Financial Times, the eight logistics organisations - including the Road Haulage Association - raised concerns over IT systems, the funding to train up customs agents and the pace of physical infrastructure being built.
They asked for an "urgent roundtable meeting" with Mr Gove, Chancellor Rishi Sunak and Transport Secretary Grant Shapps.
The letter urged ministers to take the concerns "seriously" and to "listen to the detail", or face supply chain issues after the transition period ends on 31 December.
It added that the coronavirus pandemic had demonstrated "the importance of a free-flowing supply chain", and that the supply chain must be protected ahead of a potential second wave of the UK epidemic.
A spokesman for the Cabinet Office said it had "worked closely with industry" in the development of its Border Operating Model and would "continue to do so as we move towards the end of the transition period".
He referenced a previous announcement of £50m in extra funding to support the new customs infrastructure, for IT systems and for recruiting and training new customs brokers and freight forwarders.
The UK left the European Union on 31 January, but a transition period remains in place until 31 December while the two sides negotiate a trade agreement.
During this time, the UK continues to follow some of the bloc's rules.
If a deal is not made and ratified by parliaments by the end of the year, the UK will go into 2021 trading with the bloc on World Trade Organization rules - which critics fear could damage the economy.
The EU's chief negotiator Michel Barnier said this week that he was "worried and disappointed" about the lack of concessions from his British counterpart, David Frost, after a trade deal meeting.
No 10 said it was "clear" that a deal "will not be easy to achieve".
Source: BBC News