Supermarkets have been told to make their pricing clearer to help shoppers find the best deals by the Competition and Markets Authority (CMA).
The watchdog found that historically high food price inflation has not been driven by weak competition among supermarkets but not all retailers are displaying prices as clearly as they should.
It said a lack of clear display prices could hamper people’s ability to compare products and has written to retailers warning them to make the necessary changes or risk enforcement action.
It is also calling on the Government to tighten the law around pricing displays.
CMA chief executive Sarah Cardell said: “With so many people struggling to feed their families, it’s vital that we do everything we can to make sure people find the best prices easily.
“We’ve found that not all retailers are displaying prices as clearly as they should, which could be hampering people’s ability to compare product prices.
“We’re writing to these retailers and warning them to make the necessary changes or risk facing enforcement action.
“The law itself needs to be tightened here, so we are also calling on the Government to bring in reforms.”
Ms Cardell continued: “We’ve also looked at how competition is working across the grocery retail market more widely.
“The overall evidence suggests a better picture than in the fuel market, with stronger price competition between all of the supermarkets and discounters.
“In the next phase of our work, we will examine competition and prices across the supply chain for the product categories we’ve identified.
“We’ll also continue to monitor the situation to ensure that competition remains effective as input costs start to fall.”
Sue Davies, head of food policy at Which?, said: “Which? has repeatedly exposed inconsistent and confusing supermarket pricing, which could make it difficult for shoppers to easily work out which products offer the best value, so it’s positive to see the CMA calling for immediate action from the supermarkets on this issue.
“The supermarkets must finally do the right thing by their customers and urgently act on the areas highlighted by the regulator. This includes the need to put unit pricing on promotions, such as on loyalty card offers and multi-buys, and make unit pricing clearer and more consistent.
“Government must act swiftly on its promise to update pricing rules and close the loopholes that are allowing supermarkets to unnecessarily confuse shoppers, and the regulator must be ready to take enforcement action if the supermarkets don’t act to quickly improve their pricing practices.”