Pictured: Brittany Ferries' ship, the Mont St Michel, serving the Dieppe-Newhaven route.

Brittany Ferries and DFDS are due to find themselves locked in a legal battle in France next month, as the Condor owners claim to be the victim of unfair competition on the Newhaven-Dieppe route.

In the Tribunal du Commerce – the commercial court – of Brest, Brittany Ferries is set to argue that it has lost out on £125 million since 2013 on the route between East Sussex and Northern France.

The company said it had also lodged a complaint with the EU Directorate-General for Competition.

Brittany Ferries is blaming subsidies granted by the Syndicat Mixte Transmanche, a group of French regional governments which exists to prop up the Dieppe-Newhaven route.

In an interview with French media, company president Jean-Marc Roué said the subsidies “allow DFDS to levy artificially low fares that are out of touch with economic reality”.

He added: “This draws a significant proportion of freight and passenger traffic to the Newhaven-Dieppe route, to the detriment of Brittany Ferries.”

This court case comes shortly after Brittany Ferries took DFDS to court in Jersey, in an attempt to challenge the tender process that saw DFDS selected as the island’s ferry operator.

The case failed earlier this year, and Brittany Ferries was ordered to pay Jersey’s Government and DFDS tens-of-thousands of pounds in legal costs.

The new legal case regarding the Newhaven-Dieppe route is due to be heard on 6 June in Brest.

DFDS France told French media that its lawyers were making themselves familiar with the case and the company would “reserve its answers for justice”.