Sandwich makers could be on to a good thing - research has revealed the British market is worth £2.8 billion.

The average price of a sandwich bought and eaten "on the go" is now around £1.66, and 1.69 billion were bought last year.

The survey, by TNS World Panel, is the first to put a real value on the market. Previous research has only been based on the estimated value of pre-packed sandwiches.