The Green Card would be required for motorists using their cars in the EU from 1 January 2021.

Without it, drivers could be denied entry at the country borders; they could be fined for not having the proper insurance in place and the vehicle could potentially be seized.

Admiral Car Insurance, which offers free Green Cards for customers, is also reminding drivers to allow at least a week to apply for the document if they plan on driving in the EU after 31 December.

It explains that a Green Card proves a motorist has the minimum level of cover for third party property damage and personal injury in countries that are part of the Green Card system.

Drivers towing a trailer or caravan will need an additional Green Card to prove they’re also properly insured.

Currently, Brits can drive their car in Europe without a Green Card, but this could change if there’s no deal with the EU by the end of the year.

A Green Card lasts for up to 90 days and drivers can apply for them now.

But, you must take a hard copy of your Green Card with you, an electronic version on your smart phone or tablet isn’t currently accepted by the authorities.

Clare Egan, head of motor product at Admiral, said: “As the UK prepares for the end of the transition period, and there is still a real possibility that agreement won’t be in place by 1 January, it’s important for motorists to be prepared if they’re planning to take their car to Europe.

“Having all the right protection and documentation before you travel will reduce any potential problems you could face at the border and reduce any last-minute panic.  We recommend allowing a minimum of seven days to apply for the card before you travel.

“From 1 January, motorists planning to drive in Europe will need to make sure they take their Green Card, their driving licence, their car’s logbook and a copy of their car insurance certificate with them when they drive abroad.

“If you’re taking your car to Europe before the end of the year, but will still be there after 1 January, you’ll need to get your Green Card before you head off. If you don’t have one and no deal is reached at the end of the year, you may be breaking the law and you might face a fine or your vehicle could be seized.”

The new rules also apply to the Republic of Ireland and motorists who live in Northern Ireland, planning to drive in the Republic after 1 January will also need a Green Card.

Related: See YourMoney.com’s Brexit day: How travel, shopping and rights may change for more information.