Up to 333,000 households have been victim to frosting in the last five years, according to Sainsbury's Bank.

The firm is warning car owners that leaving vehicles unattended while warming up the engine is making them vulnerable to opportunistic thieves.

"When it's freezing out it can be tempting to leave the engine running to speed up the defrosting process while you nip back inside to finish getting ready," said Joanne Mallon, car insurance manager at the firm.

However, this can have "terrible consequences", she added, warning that car insurance policies often do not cover these incidents.

Sainsbury's Car Insurance recommends that during wintry conditions, drivers should always take a fully-charged mobile phone on journeys and use major routes when possible as they are more likely to have been gritted.

LV= has revealed that despite risking death or a fine of up to £500, 2.3 million drivers are failing to wear their seatbelts.

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