Planning to make a long journeys this Christmas to see loved ones?

You might want to stock up on snacks and supplies before heading off - as research by Admiral Car Insurance found those stopping off at service stations could end up paying much more than usual.

The firm sent mystery shoppers to various stations across the UK to gather prices for a cheese sandwich, a refrigerated sausage roll, a packet of crisps, wine gums, a bar of chocolate and bottled drinks.

It found motorists could potentially end up paying 117% more for the same goods compared to a supermarket.

To save some cash, here are Admiral's tips for saving money on a long car journey:

1. Plan ahead and buy food in from the supermarket before you set off, or take a packed lunch and refillable water bottle from home.

2. Use an app such as identify places to refill water for free.

3. Fill up on fuel before you get onto the motorway.

4. Take activities and snacks for children so you are prepared if they want to stop off to avoid expensive treats.

5. Consider pulling off the motorway to a nearby supermarket if you need to re-stock as prices could be considerably lower.

6. Carry out all the appropriate vehicle checks before you start a long journey - checking tyre pressure and water levels will mean you travel safely and don't have the unexpected cost of a broken down car.