September 10, 2021 - 3:00pm

It is difficult to grasp a long story if you have a short memory. 

The problem with illegal migration across the Channel is almost 25 years old. In that quarter century, Britain and France have often quarrelled. Remember the Sangatte refugee camp? Remember The Jungle?

More often, the two countries have worked together. For 17 years now Britain’s south eastern frontier has been not at Dover or Folkestone but at Calais and Dunkirk — and at the Gare du Nord in Paris.

British Border Force officials check passports on French soil. They also inspect lorries queuing at the French Channel ports. Something like 50,000 people attempting to enter Britain without the right papers are prevented from leaving France each year. 

The latest Channel dispute — over a limited but growing number of migrations by small boat  — needs to be seen in that context. The Home Secretary Priti Patel is threatening to re-interpret the law of sea to allow Britain to turn back some boats carrying would-be asylum seekers. Her French equivalent, Gérald Darmanin, warns that any “unilateral” act could have “a negative impact” on Franco-British cooperation.

Patel and Darmanin are curiously similar figures. Both are regarded as dangerous hard-liners by the Left in their own countries. Both are themselves from migrant backgrounds — Patel’s family from India via Uganda, Darmanin’s from Algeria and Malta via Tunisia.

The two “interior ministers” should understand one another very well. Darmanin’s blunt letter to Patel this week carried no specific threats but it contained a pointed reminder — Britain will lose more than it gains if it falls out with France on cross-Channel migration. 

Some senior French politicians are already calling for an end to the 2003 Treaty of Le Touquet, which sets up the so-called “juxtaposed controls” allowing British border checks in France (and French checks at Dover and St Pancras). The critics include the president of the northern French region, Xavier Bertrand, the leading centre-Right candidate in the presidential election next April. 

During the last election the British-border-in-France was criticised by another candidate. His name was Emmanuel Macron.

Arguably, the Le Touquet treaty is also in France’s own interest. Without it, even more migrants or refugees would pile up in the Pas de Calais trying to find ways of reaching Britain.

Why don’t they just stay in France, you ask? The great majority of the illegal migrants who reach France do just that. The “Calais migrants” are a minority. They are determined to go to Britain because they speak a little English or because they have been convinced by smuggling gangs that the streets of Dover are paved with gold.

They are a perpetual problem for both countries — hence the treaty. There is, however, a growing drum-beat of French opinion that they are a British problem and that Britain’s border should be repatriated to Kent.

The UK would then face an influx of asylum seekers which would make the present dinghy and small boat traffic look like a trickle. Priti Patel would be well advised not to push out the bateau too far.

John Lichfield was Paris correspondent of The Independent for 20 years. Half-English and half-Belgian, he was born in Stoke-on-Trent and lives in Normandy.