A hard Brexit could lead to Operation Stack-level queues on a daily basis, the chief executive of the British Ports Association has said.
Richard Ballantyne told City A.M. that ports on both sides of the Channel faced extreme lorry tailbacks, akin to those that caused chaos in 2015 during the Calais migrant crisis, if no deal on the future customs arrangements is reached before March 2019. The queues could result in wastage of fresh produce, additional cost to business and consumers, and annoyance for those who live near the routes.
He said: "Even a 30-second check could cause substantial delays for roll-on, roll-off (Roro) ports. Terminals are very space efficient - they don't have redundant land - so if you have lorries stacking up they're either staying on the ferries or the roads...
"In a worst case scenario, that would mean Operation Stack level queuing on a very frequent basis, possibly daily."
The roads leading into Dover would be hardest hit, but all Roro ports including Holyhead and Portsmouth would be affected, he said. Traders might shift lorries onto different routes "but that would probably result in higher costs for traders, and ultimately consumers", Ballantyne said.
"It could have a strong economic impact," he added. "Experts are saying growth is slowing down - this could be another thing that adds pressure to inflation."
Ballantyne stressed this was "not a political view" and urged the government to push forward with the second option outlined in DexEU's recent customs position paper, which set out a vision for "a new customs partnership with the EU, aligning our approach to the customs border in a way that removes the need for a UK-EU customs border".
There may still be minor disruption with this option "but it wouldn't represent the doomsday scenario of all traffic being held at ports," he explained.
The chances of a hard Brexit have risen in recent weeks, with Cabinet sources quoted last weekend as giving it a one in three chance.
Yesterday Brexit secretary David Davis told the Commons he expected the talks over the divorce bill to last "the duration" of the negotiations. Brussels has repeatedly said it will not move on to discuss trade or transition until a figure has been agreed.
The EU Withdrawal Bill is to receive its second reading today (7 September) ahead of a vote on Monday. Labour MPs are being whipped to vote against the bill.