If Johnson cannot expel enough EU fishing boats from U.K. waters, a no-deal Brexit would surely ensue, creating chaos and costs for all and ruin for some.
The French, Britain's fiercest political rival for access to U.K. waters, know about symbolism — and timing — too.
As well as France, the Netherlands, Belgium, Ireland and Denmark are among those directly implicated by the potential closing off of U.K. waters.
Deas said he expected there to be protests from disgruntled EU fishermen — especially French ones — if there is a deal that sees quotas reduced.
Most agree Boulogne would be a prime target because so much U.K. fish is exported through there, and a blockade is relatively easy to achieve.