Despite the raft of alternative offerings, sandwiches continue to form the main part of the majority of the nation's lunchboxes,

featuring in almost 75%, according to TNS.

Home-made sandwiches are holding their own against pre-packed rivals, despite the huge growth in sandwich outlets and coffee chains.

"There is a far bigger choice now of healthy, tasty fare. However, many still choose to buy stock items for the fridge and to make their own," says Deborah Carter creative head of innovation at brand agency Dragon.

Richard Esau, director of marketing at the UK's largest sandwich manufacturer Greencore, echoes this view. "People don't tend to buy sandwiches to put them in a lunchbox," he says.

"Food is sometimes brought from home to ­supplement a fresh sandwich bought at lunchtime. Typically fruit, crisps and confectionery are brought from home for this purpose. Where sandwiches appear in lunchboxes, they are almost always made at home."

About ten billion sandwiches are thought to be consumed in the UK each year, of which more than eight billion are home made.

Still, both the pre-packed and the home made sandwich sectors are showing strong growth, boosted by the increasing tendency to eat out of the home.

According to figures from the British Sandwich Association, 1.8 billion pre-packed sandwiches are sold on average each year. This figure is likely to keep growing, says Somerfield's category buyer for sandwiches Marc Matthews.

"The bought sandwich market is growing healthily with people continuing to look for convenient,

time-saving solutions. As the proportion of food eaten out of the home continues to grow, so will the demand for bought sandwiches."

Matthews' view is supported by a recent report by Mintel that suggests the bought sandwich sector is set to grow nearly 30% over the next six years, with premium ranges growing at the fastest rate.

As a response to this, Ginsters has introduced a number of premium tier launches, most recently a deep fill 'less than 350 calories' Chicken Tikka Sandwich.

Designed to plug a gap in the market for full-flavour, low-calorie eats, the ­newcomer is made with authentic tikka spices and chunks of chicken tikka breast.

The sandwich sector has not escaped the trend across the food industry for smaller portion sizes, with Pret à Manger leading the charge when last year it launched a half sandwich aimed at people with smaller appetites. A small number of retailers have recently adopted this format.n