Budget airlines 'take snackers for a ride'

The average price of food and drink – excluding hot drinks – on low-fare carriers is 374 per cent more than at supermarkets, the survey by price comparison site travelsupermarket.com found.

Snacks on no-frills airlines are also generally more expensive than prices at airports, the survey revealed.

For example, a sandwich that costs about 2 in a supermarket and 2.40 at an airport costs as much as 4.39 on Ryanair and 3.95 on Flybe.

The biggest mark-ups were on items such as crisps, shortbread and muffins.

A website spokesman said: "Airlines can get away with charging extortionate prices because once you're onboard there's nowhere else to go. Prices vary significantly across airlines so by bringing your own you can avoid having to think about it at all."