Channel Islands-bound lorries at Portsmouth will be given priority over others if the UK leaves the European Union without a deal.
The UK government's Brexit contingency plan, Operation Yellowhammer, warned of potential delays at the ports and shortage of supplies in the Channel Islands.
In its own planning to manage potential disruption caused by a no-deal Brexit, Jersey's government warned it would have a 'significant and swift impact' on the availability of medicines and many foods on islanders' shelves if there was disruption at the ports.
However, Portsmouth City Council says freight bound for the Channel Islands will get priority, no matter how busy the port gets in the event of a no deal Brexit.
Portsmouth currently deals with around 500 lorries a day, but this could run into the thousands if companies opt to use that port rather than Dover.
In a letter to the government, the Hampshire Local Resilience Forum called on the government to offer more support to the area to deal with the increase.
The assumption that 75% of laden HGVs arriving at the Port will not be border-ready - and so will need to be turned around - is a major challenge. We believe that our contingencies may quickly become overwhelmed. We strongly believe Government actions are required.
Haulage firms have been planning since the previous Brexit deadline of 29 March when Operation Brock, a test of how Dover could deal with a backlog at the port, was carried out.Andy Jehan is from a local freight haulier company. He says he is confident their lorries will get through.
We've all got permits that will allow us to bypass the inland check points that are going to be set up. So that will allow vehicles that are heading to the Channel Island ferries to be able to pass the road blocks and make their way to the ferry on time.
There remains a concern that the two main routes into Portsmouth - the M27 and the A3 - will become gridlocked, with no such fast lane. The port itself is on an island with limited overflow parking.
Many of those lorries will use Condor services to cross the Channel and reach the islands. The company operates six days a week for 52 weeks of the year, carrying both freight and passengers to and from the UK.
The company's CEO Paul Luxon is confident that the plans they have put in place will keep goods moving.
We're not complacent, we're not sure what the outcome will be on 31 October, but we believe we've put practical operations in place to ensure there should be a seamless continuation of supply chain into the islands. >
Mr Luxon also says that arrangements are in place to redirect freight to Poole, if necessary.
It wouldn't be ideal of course, because it's an hour and a half from Portsmouth which is where all the just in time supply chain is centred so obviously it would be incredibly cumbersome for our logistics operators, but it would be a backstop option.