FRENCH President Emmanuel Macron is expected to demand Britain coughs up the money to pay for the cost of setting up new customs posts at its Channel ports after Brexit.
French politicians and officials believe the UK should be forced to contribute to the cost of tighter border controls, even after Britain quits the European Union.
Britain currently helps pay for the customs arrangements at Channel ports, such as Calais, under the Le Touquet Treaty, which means Britain effectively pays to manage its border on the French mainland.
It is understood President Macron will raise the border issue during a meeting with Theresa May for an Anglo-French summit in January.
French officials have said the cost of preparing for UK facing border points will cost more than the new arrangements in Ireland.
The French ports of Calais and Dunkirk both serve Dover, which is the busiest sea port in the world.
President Macron is facing internal pressure to demand from Mrs May a contribution toward the cost of the new arrangements.
Jean-Paul Mulot, envoy to the UK for the ports of Calais, Dunkirk, Boulogne and the Eurotunnel entrance, said the cost has been estimated at hundreds of millions of pounds and should be shared between the entire European Union.
Prominent Brexiteers have rubbished the French demands, but Mr Mulot said it is in both sides interest to have a smooth border, adding the UK would “agree to provide some funding eventually”.
The Frenchman said: “At the height of the migrants’ crisis two years ago when cross-Channel traffic was being disrupted, Volkwagen’s Oxford factory considered closing temporarily because it was running out of parts.
“About 800,000 car parts cross the Channel each day, and huge quantities of food too.”
Conservative MP Iain Duncan Smith was amongst the Brexiteers to deride the demands.
He told the Telegraph: “No other country is asking for money, not Holland, not Belgium, and Mrs May should remind Mr Macron that he stands to benefit from this arrangement because France sells more goods to us than we sell to them.
“Theresa May can smile sweetly at Mr Macron and tell him there will not be a penny more than has already been agreed.
“We have already said how much we will pay, and if the EU wants to give some of that money to France, that’s up to them.”