The police force has warned drivers who leave their cars running to heat up and defrost while they keep warm in the house may find that their car insurance policy becomes invalid.

A policeman from Devon and Cornwall Constabulary explained that by motorists leaving their keys in the ignition of an unattended motor, drivers are creating a chance for thieves.

PC Mark Humphries stated: “Unfortunately, if a vehicle is stolen in this manner, people will also get a frosty reception from their insurance company, as loss from leaving keys in an unattended vehicle leaves policies void.”

In addition, drivers may not realise that by leaving their cars running on a frosty morning, they may actually be committing an offence.

Norfolk Constabulary's Inspector Dave Cuff recently observed: “At this time of year, motorists de-ice or warm up their vehicle by leaving the engine running. If it is parked on a road and is unattended, then the motorist commits the offence of 'quitting'.”

Drivers who are found guilty of quitting their vehicle with the engine running could also face a fine.