It’s certainly a ‘geste audacieux’. From today, Carrefour is calling out shrinkflation at the shelf edge, with orange barkers notifying customers when products sold in its stores have decreased in size or weight but not changed (or increased) in price.

Big brands – around 150 products in all with more to come – are now being shamed by the 13cm square alerts, among them Lay’s crisps (PepsiCo), Lipton Iced Tea (PepsiCo), Amora mayonnaise (Unilever) and Dolce Gusto Grande Intenso coffee pods (Nescafé).

“This product has seen its weight drop and the price charged by our supplier increase. We are committed to renegotiating this price,” the signage reads.

Carrefour CEO Alexandre Bompard, on the media rounds last week, said: “This way, we will have the most reliable information possible for consumers, because it is unacceptable to do that for the consumer.”

Carrefour is not the first French supermarket to name and shame its shrinkflating suppliers. Earlier this summer, Intermarché put up posters in stores reading “Findus has decided to increase its prices while reducing the quantity of product. Our role is to offer you your favourite brands but also to alert you to these behaviours.”

Could UK supermarkets spring a similar tactic on suppliers?

Providing a boost to own label

Bold moves can mean big prizes. Nearly three-quarters of Brits had noticed examples of shrinkflation in their grocery baskets, according to a recent Barclays survey, with chocolate, crisps and biscuits the most frequently cited.

Calling it out could boost even more of a shift towards own label, given a fifth of those surveyed by Barclays were already switching to alternatives whose sizes hadn’t changed.

And while potentially currying favour with consumers as their honest-to-a-fault protector against getting ripped off, the shaming is a formidable weapon in supplier negotiations, which French pundits predict “will be brutal”.

Of course, there are huge risks too.

Brands are – quite understandably – not happy. Findus – having been shamed by Intermarché for reducing the weight of its hash browns pack from 600g to 590g and increasing price per kilo by 68% – said the practice “has no place in a commercial relationship of trust that we have maintained with Intermarché for so many years”. It accused the chain of misleading customers and claimed it lost money on every box sold before the change.

Once exposed, there seems little chance the retailer/supplier relationship can be repaired. And with gloves off, it wouldn’t take the marketing might of a PepsiCo or Unilever to get consumers to ask: “If supplier costs are increasing, why aren’t supermarkets themselves absorbing the rises, rather than me?” It’s a question already going begging, and trust in supermarkets is at its lowest level since the horsemeat scandal.

Supermarkets need to be confident they’re squeaky clean

And as shrinkflation becomes more common – hitting biscuits, chocolate, bread, confectionery, booze, mayonnaise, meat-free, soap, washing powder and more in recent months – what consumer would want to come back to a store plastered in rip-off warnings?

Supermarkets would need to be confident they themselves are squeaky clean when it comes to shrinkflation before committing. Few are. Carrefour has already been ‘caught out’ with consumer advocacy group 60 Millions finding examples in its own label range. The supermarket, for example, earlier this year added a two-pack of lettuce to its €0.99 ‘anti-inflation basket’ promotion. It previously sold a pack of three for the same price.

It rather took the wind out of the sails of Bompard in one TV appearance when questioned about the practice.

“We may have had some [examples]. It could have happened. It’s possible, I don’t believe it… But if there was, there won’t be any now. And we really had very, very few, if we had any,” he conceded.

Shrinkflation is a tricky thing for retailers to deal with. Calling it out is a daring strategy. If it works for Carrefour, qui vivra verra.