British motorists have become a safety menace on France's roads, regularly flouting the speed limits after crossing the Channel, French police say.

Hospitals in the north of France report a high number of British casualties as holidaymakers rush to catch ferries or the shuttle home.

The problem is so serious that officers from England are being sent to patrol motorways near northern French ports in an attempt to convince Britons that they are not immune to a recent crackdown on speeding on French roads.

In a four-hour period last weekend, on the A26 motorway near Saint-Omer, a Franco-British patrol stopped 30 cars for breaking the 130km/h (80mph) limit. All but two were from Britain. British drivers have committed half of the most serious speeding offences - over 125mph - in the region this year.

“Often British drivers pretend they do not understand and they think that the French police have it in for them,” Lieutenant Patrick Vanderstaerten, of the Pas-de-Calais police, said. “It's an old cliché from the old Anglo-French quarrel.”

The British, who used to be seen in France as cautious and courteous drivers, have overtaken the Germans as speed fiends since 2002, when President Chirac installed thousands of speed cameras. French drivers have begun obeying the limits, but many foreigners have not, because Europe has not applied an accord reached last spring on the cross-border enforcement of fines.

Britons' sense of immunity is felt across the board, from holidaymakers to the owners of sports cars who stage informal races, police say. “The mentality of letting go across the Channel seems to be the same one that makes les Anglais get drunk as soon as they leave their country,” one officer said.

Lewis Hamilton, the Formula One driver, lost his right to drive in France last December when he was stopped on the A26 near Calais doing 122mph in a Mercedes.

Dozens of Britons have had their vehicles confiscated - sometimes permanently - for speeding in France in the past two years. Police can also suspend a licence for speeds 25mph above the limit, and impose fines of up to €1,500 (£1,200).

The cross-channel co-operation between police forces is expected to become a regular event, with French officers also patrolling in Kent, Lieutenant Vanderstaerten said.

Times Recommends

• Henning Mankell: ‘If Wallander was alive, I wouldn’t be a friend of his’
• Secret society's skull and crossbones for sale
• Nigerian leader vanishes after medical treatment