Friday's threatened action comes after the European Union gave Britain a deadline of December 10 to resolve the issue of licences sought by French fishermen, who complain that post-Brexit requirements are too onerous.

"We are disappointed by threats of protest activity," Prime Minister Boris Johnson's spokesman told reporters.

"It will be a matter for the French to ensure that there are no illegal actions and that trade is not affected," he said.

"We continue to monitor the situation closely."

A union representing French fishermen said it planned to block ferry traffic into three Channel ports as well as the movement of goods through the tunnel between France and Britain.

The issue has contributed to growing post-Brexit strains between London and Paris, now exacerbated by a migrant disaster in the Channel that cost 27 lives on Wednesday.

Tensions over the fisheries dispute even spiralled into a brief naval standoff in May when dozens of French trawlers massed in front of Jersey's Saint Helier harbour.