Shoppers could soon find it easier to compare food prices in-store after three of the UK's biggest supermarkets pledged to improve labelling to make prices and special offers easier to understand.

Aldi, The Co-operative and Waitrose say they'll improve their labels to back consumer group Which?'s Price It Right campaign. Morrisons signed up to the scheme last year. (See our Supermarket Shopping Tips to save on your groceries.)

As part of the campaign, which argues that food prices and special offers are too confusing and that unit prices need to be displayed simply and clearly, Which? wrote to 10 supermarkets asking them to commit to the following:

  • Display a consistent unit price by using the same unit measurement, eg, kilograms or grams.
  • Include the unit price of food items on promotions in-store.
  • Ensure unit pricing labels follow, where possible, RNIB guidelines on making them clear to people with sight impairments.

According to Which?, of the six remaining supermarkets, Sainsbury's has been working on making prices transparent over the last 18 months, while Lidl and Tesco are also making "active steps" towards simpler pricing.

Asda says it will look at improving its labelling, but Which? says Iceland and Marks & Spencer have yet to reply to its letter.

Research from the consumer group shows 78% of people actively look out for the best price for their groceries, while 43% compare prices when shopping in store.

Which? executive director Richard Lloyd says: "Hard-pressed shoppers want to know at a glance what the cheapest deal is without having to get their calculators out.

"So it's a win for consumers that four major supermarkets have committed to improving their labels."