Called Locate, the new service involves travellers registering their travel details on a newly-created part of the FO website.

Travellers will give information about their journeys as well as providing details of friends and family who can be contacted in an emergency.

The initiative coincides with an FO survey which showed that two in three people did not know actually where their loved ones were travelling.

The survey also showed that more than half of Britons go abroad without leaving journey details with friends and family.

In 2006, Britons made an estimated 68 million foreign trips. It is reckoned that around five million people stay abroad for a year or more.

As many as 20% of Britons caught up in incidents abroad felt compelled to let someone know they were all right, but communications can be tricky at times, the FO said.

Foreign Office Minister Meg Munn said: "It's great to get off the beaten track when we're away from home, but things can change very quickly in any country. In our survey more than nine out of 10 Britons said they would feel reassured to know that in the event of an emergency abroad, the local embassy could quickly find their location.

"Telling us where you will be, whether it's a short trip or you're travelling for a year, could help us either to get to you if you are in trouble, or know that you are safe so that we can concentrate our resources on helping those in need."