Driving law change alarms thousands of British holidaymakers heading for half-term holidays in Florida

On the eve of Britain's main half-term holiday, the Foreign Office has warned holidaymakers heading to Florida that anyone planning to rent a car in the state must hold an International Driving Permit (IDP).

The move came after The Independent alerted the FCO to a new law that threatens visiting motorists with jail if they do not carry the permit in addition to their national licence.

Until this year, drivers needed only the standard British photocard licence with the green counterpart - as with the rest of the US. But Florida's legislature has tightened up the motoring rules, making it mandatory for overseas visitors to carry an IDP as well as their national licence.

If a driver is pulled over by Highway Patrol officers, or is involved in an accident, the penalties for breaking the new law are harsh. A spokeswoman for the Florida Department of Highway Safety and Motor Vehicles, Kirsten Olsen-Doolan, told The Independent that police who encounter British motorists driving illegally have two options: “Arresting the driver and taking him/her to jail, or giving the driver a citation with a mandatory court appearance.”

A Foreign Office spokesperson said: “We have raised changes to Florida driving laws with the Florida authorities. The Florida Department of Highway Safety and Motor Vehicles has advised us that they are urgently looking to amend the law for those countries who issue driving licences in English.”

And overnight the Florida authorities said that the new legislation would not be enforced in the short term.

Few British motorists carry the IDP, because the vast majority of holidays and business trips are to places that do not require it. The permit, which costs £5.50, is issued by the AA and RAC by post. They can also be obtained in person at Post Offices - but only by 88 branches in the entire UK, which is fewer than one per cent of the total.

About one million UK citizens visit Florida annually. Rosie Sanderson, who runs the AA's International Division, said: “It has thrown the fly-drive market into chaos, with a lot of conflicting advice”.

The leading rental firm, Hertz, has confirmed its Florida offices would insist on an IDP as well as a national licence, and said: “It is the responsibility of the driver to obtain a permit”.

Avis told The Independent that it required “All UK customers to have an International Driving Permit in order to hire a car in Florida”. But the UK's leading car-broker, Holiday Autos, said that its US supplier, Alamo, would not insist upon an IDP. The permit would be needed “only if the full licence held by the driver/hirer was not in English”.

The change in the law was identified by Elle Hubbard of the rental broker Tripwheels. She told The Independent: “We had hoped that perhaps there might be a 'grace period' or leniency shown given that many tourists will be already in Florida and unaware of the new rules. However, we were told 'Law enforcement is there to enforce the laws, we are not selective nor can we disregard the law'.”