A former military airfield in Dumfries and Galloway could be transformed into an emergency lorry park to cope with post-Brexit delays at Cairnryan.
Transport Scotland confirmed it was in discussions with the Stairs Estate to use the Castle Kennedy Airfield.
The UK has still not agreed a trade deal with the EU ahead of the 31 December deadline.
If no deal is reached, the UK and EU would trade under World Trade Organization rules.
This outcome would lead to each side imposing taxes – or tariffs – on imported goods, potentially leading to higher prices.
Even if a deal is reached, goods entering the EU from Great Britain will face large amounts of new paperwork and checks, including customs declarations, rules of origin checks and product safety certificates.
There are fears this could lead to queues of lorries backing up at ports.
Transport Scotland said it had an “agreement in principle” to use the airfield, east of Stranraer, to park lorries waiting to cross on the ferry to Northern Ireland.
A spokesperson added: “While we still need clarity from the UK government on the terms of exit, including the requirements for checks on goods moving from GB to NI, at this stage we do not expect a significant increase in traffic or delays at Cairnryan.
“Nevertheless we have been engaging with ferry operators who have assured us that they have capacity to cover increased demand on the Cairnryan/Larne routes.
“We have also worked with local resilience partners to develop a contingency plan in case of traffic disruption at Cairnryan and are now moving to test that plan.”
The Scottish Labour leader of Dumfries and Galloway Council, Elaine Murray, said the authority was not involved in the negotiations with the airfield.
But she told BBC Radio’s Good Morning Scotland there were concerns that lorries could end up blocking the A75 and A77 if the port could not cope with the traffic.
“We’ve also got issues around the export of animal products and the export of live animals, of which a number are exported from our region,” she said.
“We’ve had several scenarios which the council has been planning around for the last couple of years or more, trying to put in mitigation for the impact of those.
“In our view it’s very late in the day to be talking about the emergency lorry park. We would have like that to have been settled a lot earlier so local people knew what was happening.”