Customers being led up the supermarket aisle

Supermarket shelves are full of special offers, but Which? has found that some of them aren't that special and even break government guidelines.

Which? investigated offers at high street and online supermarkets to check if they complied with new government guidelines, introduced in May, to ensure that offers don't mislead customers. The rules state that before an item goes on offer, it should be at the advertised higher price for 28 days in that store.

The consumer organisation found the following offers that broke the guidelines:

Marks & Spencer cherries were marked as half price at £2.49, which implies a saving of £2.49, but customers were actually only saving 50p on the previous price of £2.99. The cherries had only been sold at £4.99 for 17 days, a month before the offer.

Waitrose blueberries were only at the higher price (£3.99) for two weeks before being sold at ‘half price' (£1.99) for six weeks.

Sainsbury's Gallo Cabernet Zinfandel and Chardonnay Sauvignon had ‘£1 off' at £3.99 for five weeks, then briefly returned to the higher price of £4.99 for one week - before going back to £1 off.

Tesco strawberries and Marks & Spencer bacon were ‘on offer' for the whole three-month investigation. These offers don't actually break the guidelines, but can hardly be described as ‘special'.

Which? also carried out a survey which shows that almost three quarters of its members think that special offers are good value and more than half often buy things they aren't intending to because they are on offer. Three in 10 said that buy-one-get-one-free (Bogof) offers cause them to throw away food.

The UK wastes 6.7m tonnes of food a year - roughly a third of everything bought. Families with children in the UK waste an average of £610 a year on food that ends up being thrown away.

Nikki Ratcliff, Head of Services Research, Which?, says: "We all like a good deal, but ‘special offers' encourage us to spend more than we would otherwise and may make us buy food that we throw away. Supermarkets need to comply with the spirit of the new government guidelines and stop misleading consumers into thinking they're getting great deals when they're not."