FRANCE is set to deliberately snarl up Christmas shipments to and from Britain in revenge over fishing rights, officials fear.
Downing Street is braced for more confrontation with President Emmanuel Macron as talks over licences for UK waters reach a crucial stage.
French skippers are threatening to blockade Calais from Saturday morning if negotiations on a fishing deal fail.
Paris has set midnight on Friday as the deadline and is preparing reprisals, which may be triggered next Monday.
It wants to slap extra import taxes on British goods but is unlikely to win the necessary backing from the EU.
Instead, it could cause backlogs at Calais and Dover by ordering more physical checks. Other measures will include hiking electricity in Jersey and blocking UK boats from French ports.
But French officials privately admit they do not want to make strained relations with Britain even worse.
It comes as an EU row brews after Brexit minister Lord Frost dismissed its opening offer on Northern Ireland border checks.