Ministers have been told that they risk paralysing cross-Channel trade with Europe unless they agree a Brexit deal that is acceptable to French fishermen.

In what is being described as a “nightmare” scenario, Whitehall officials have told ministers that there is a “very realistic chance” that cross-Channel ports would be blockaded by EU fishing fleets in the event that no trade deal is agreed. They are particularly concerned that Calais is uniquely vulnerable to even a small-scale protest against attempts to restrict the access of EU fishing fleets to UK waters.

Boris Johnson has said that EU fishing ships would no longer have access to British waters unless a deal is struck by December. The government has invested in new fishery protection vessels.

Before the