Stena Line has moved one of its ferries from Belfast to Rosslare in what it has called a "Brexit busting move".
When the Stena Embla arrived in Belfast on 2 January the company said it would be concentrating on transporting freight between Belfast and Liverpool.
However, on Wednesday the company tweeted that it would be deployed on the Rosslare to Cherbourg route.
Businesses and hauliers have faced difficulties transporting goods from GB to NI post Brexit.
Breaking news: in another Brexit-busting move our new vessel Stena Embla is NOT starting from Belfast as planned. She's being deployed on our Rosslare to Cherbourg route from tomorrow. It can add 3km of trucks & 175 comfy cabins - that's a lot of sleep-happy truckers. #brexit https://t.co/IrkDmnS8Np— Stena Line Group (@StenaLine) January 13, 2021
The UK officially finished its formal separation from the EU on 31 December, 2020.
Since then there has been disruption to trade across the Irish Sea border.
Northern Ireland remains in the EU single market for goods and will continue to enforce EU customs rules at its ports.
The Irish Sea border means that most commercial goods entering NI from GB require a customs declaration.
In a statement, Stena Line said the relocation was "due to the current Brexit related shift for direct routes and increasing customer demand".
"Given the short-term market distortion, we have decided to temporarily deploy our new Stena Embla vessel on the Rosslare - Cherbourg route," said Paul Grant, Stena Line's Irish Sea trade director.
"Clearly Brexit has created an increase in the demand for direct freight routes, and in particular driver accompanied freight, so the addition of Stena Embla, whilst temporary, plus the recently introduced Stena Foreteller to the route will provide a welcome addition for our customers at this time."