The report from the Competition and Markets Authority (CMA) suggested supermarkets “could do more” to broaden access to loyalty schemes, which it found do offer genuine savings.

Supermarket loyalty cards do offer genuine savings, the UK's competition watchdog has found, but it said people should still shop around. The Competition and Markets Authority (CMA) examined 50,000 products on loyalty price promotions across Tesco, Sainsbury's, Morrisons, Co-op and Waitrose.

Britain's competition regulator said on Wednesday that supermarket prices offered through loyalty schemes do provide genuine savings.

The CMA said it had found very little evidence of supermarkets inflating their 'usual' prices to make loyalty promotions seem like a better deal.

The Competition and Markets Authority has been investigating loyalty schemes at major supermarkets including Tesco, Sainsbury's, Asda, Morrisons and Waitrose since November last year

British supermarket prices offered through loyalty schemes provide genuine savings, the competition regulator ruled on Wednesday, providing a boost to the major players who are increasingly relying on them to attract shoppers.