French game producers are suing cross-Channel ferry companies for refusing to transport baby pheasants and partridges to Britain, alleging pressure from anti-hunting activists.

Two major producers, Gibovendee and Envol de Retz, are suing French giant Brittany Ferries, accusing them of "discrimination based on political opinion", their lawyer Alexandre Varaut told AFP on Wednesday.

The companies, which sell both chicks and eggs for breeding or to estates for hunting, are also taking on British-based P and O ferries and Danish shipping company DFDS in separate courts for the same reason.

The two firms, both based in western France, allege that the shipping companies have been refusing to carry their chicks since 2015 over fears of harm to their brand image, largely "because of anti-hunting pressure".

Brittany Ferries declined to comment, while P and O merely confirmed that they stopped transporting chicks two years ago.

The case against Brittany Ferries was brought to court last month in the western city of Brest, while cases against P and O and DFDS have been brought before courts in Boulogne and Dieppe to the north.

Brittany Ferries told the breeders the company would not transport the chicks because of possible "trade repercussions linked to boycott threats by anti-hunting associations", according to the claim filed in Brest.