Consumer lobby group Which? has slammed sandwiches from Asda, Marks & Spencer and Subway as containing "shocking" amounts of salt, sugar or saturated fat and is calling for nutritional information to be available at point of sale for all sandwiches.

Research published in Which? magazine found that Subway’s six-inch Meatball Marinara had 4.7g of salt - more than 75% of an adult’s 6g recommended daily intake; M&S’s Wensleydale & Carrot Chutney had 25.5g of sugar - equivalent to more than five teaspoons; and Asda’s Vintage Cheddar Ploughman’s (no mayo) had 15.2g of saturated fat, more than 75% of a woman’s maximum guideline daily amount. Both the Asda and M&S sandwiches had front-of-pack nutritional information labelling.

Martyn Hocking, editor of Which? magazine, said: "A sandwich might seem a pretty healthy option, but there can be shoc-king amounts of salt, sugar and fat in some of them and you’d have no idea if they’re not labelled. Some coffee shops and sandwich chains have signed up to the Food Standards Agency’s pilot scheme to provide calorie information when eating out, but all food outlets should provide this as a matter of course."

At the British Sandwich Association, director Jim Winship said that providing nutritional information for sandwiches was difficult in foodservice. "For independent sandwich bars and bakers it’s a major problem because they don’t have the expertise or technology to analyse salt content in their products. Then there is the question of how you provide the information - do you put it on the paper bag, on a board on the wall or online?"

He added that Which? was "jumping the gun" with its report. "It should have waited until the FSA’s pilot scheme on calorie information has been completed," he said.