Queues of up to 7,000 heavy-goods vehicles could develop in southeast England from January if Britain leaves the European Union without a Brexit trading deal, the government forecast Wednesday.

Outlining a "reasonable worst-case scenario", senior minister Michael Gove said the government remained committed to a deal with the EU but urged businesses to prepare.

Based on current estimates on companies' preparedness, the government said it was likely that only 30 to 60 percent of trucks laden with goods would arrive at Dover and other ports in southeast England with the right paperwork to cross to France.

Gove told parliament this could lead to queues of "up to 7,000 HGVs in Kent" from January 1, holding up goods for two days. 

"These queues and associated disruption and delay would of course subside as unready businesses who had their goods turned back at the French border would not want to repeat the experience," he said.

"But it is clearly far better that everyone is aware now of what is needed to prepare rather than to face additional disruption next year."

Britain left the EU in January but remains bound by the bloc's rules under a transition period that expires on December 31. 

Beyond that, there is no certainty of a new trading arrangement with the two sides locked in difficult negotiations.

In case of no-deal, the government is developing giant lorry parks in Kent to prevent gridlock on the road system leading in and out of London. 

It also proposes to issue special permits for trucks heading to the cross-Channel port at Dover and the Eurotunnel road terminal at Folkestone.

That provoked ridicule on social media, with suggestions that Kent could become another Brexit border flashpoint like Northern Ireland.

But industry groups say the onus is on the government to fix critical areas on the UK side, such as information technology for new customs procedures, by December 31.

Elizabeth de Jong, policy director at Logistics UK, said the government and companies faced a "huge challenge". 

"With so much still to do, it is vital that all parties work together to keep the flow of trade moving smoothly between the UK and EU," she said in a statement.