Carrefour has placed stickers on 26 products, including ice tea and chocolates, that have reduced in size despite a reduction in the price of raw materials.
The labels read: “This product has seen its volume or weight fall and the effective price by the supplier rise.”
The warning will last until the targeted suppliers agree to price cuts and could be extended to a greater number of goods.
The move comes as retailers prepare to meet with the world’s biggest brands for negotiations on price, which will begin soon and end on October 15.
Stefen Bompais, director of client communications at Carrefour, told Reuters that the “aim in stigmatising these products is to be table to tell manufacturers to rethink their pricing policy”.
The company’s CEO Alexandre Bompard has repeatedly accused consumer giants of not cooperating in efforts to cut the price of goods.
Carrefour said that a bottle of sugar-free peach-flavoured Lipton Ice Tea, produced by PepsiCo, shrank to 1.25 litres from 1.5 litres – a 40 per cent increase in the price per litre.
Unilever's Viennetta ice-cream cake shrank to 320 grams from 350 grams, according to the supermarket chain.
A report published in July by Which uncovered similar examples of “shrinkflation”. A pack of Lurpak butter was found to have been reduced by 50g in recent months, while Whiskas cat food pouches had shrunk by 15g.
Four-fifths of shoppers are worried about supermarket “shrinkflation” and are turning away from their favourite brands as a result, according to a survey by Barclays.
Businesses are allowed to change the size and cost of their products but can not suggest that the packaging contains more than it actually does.
August has been a muted month for spending, with year-on-year growth of just 2.8 per cent noticeably lower than July’s 4 per cent, according to the Barclays Consumer Spending Index, based on the bank’s debit card and Barclaycard credit card transaction figures.
Supermarkets and food and drink specialist stores saw weaker growth of 4.5 per cent and 4.9 per cent respectively as inflation slowed.