French supermarket Carrefour has put stickers on its shelves this week warning shoppers of “shrinkflation” – where packet contents are getting smaller while prices are not.

Lipton Ice Tea, Lindt chocolate and Viennetta ice cream are among the products being named and shamed.

Shoppers are being told if bottles are smaller or pack contents lighter.

Carrefour said it wanted to put pressure on the firms making the products to keep prices down.

“Obviously, the aim in stigmatising these products is to be able to tell manufacturers to rethink their pricing policy,” said Stefen Bompais, director of client communications at Carrefour.

Carrefour has identified 26 products that have shrunk, without a price reduction to match, made by food giants including Nestle, PepsiCo and Unilever.

Carrefour said Guigoz infant milk formula produced by Nestle had gone from a pack size of 900g to 830g, for example.

A bottle of sugar-free peach-flavoured Lipton Ice Tea, produced by PepsiCo, shrank to 1.25 litres from 1.5 litres, the supermarket said.

Viennetta, made by Unilever, has shrunk from 350g to 320g.

Carrefour, France’s second largest grocer, is highlighting the products in question with signs on the shelves reading: “This product has seen its volume/weight fall and the effective price charged by the supplier rise.”

Unilever, Pepsico and Nestle have not commented on Carrefour’s move.

French retailers and food manufacturers have come under pressure to reduce prices, just as in the UK, as shoppers struggle with sharply rising prices.

In June French Finance Minister Bruno Le Maire summoned 75 retailers and consumer groups to a meeting about prices, and has accused manufacturers of not toeing the line on inflation.

British consumer groups have also warned of “shrinkflation” affecting the value of common items from cat food to chocolate biscuits.

But it is unlikely that UK supermarkets would follow in Carrefour’s footsteps, according to retail expert Ged Futter, because the strategy risks “poisoning” relationships between retailers and food firms.

“This is a very blunt way of of trying to compete,” he said. “To do that with your manufacturers, it won’t help.”

Supermarkets use the same “shrinkflation” tactic with their own-label products, he added, aiming to keep to a certain price point, for example £1, by introducing cheaper ingredients, or making portions smaller to manage rising costs.

Given that, calling out brands for doing the same thing would be “people in glass houses throwing stones”, he said, and would risk accusations of hypocrisy.