Lloyds Pharmacy’s parent company is facing a “detailed investigation” by the Competition and Markets Authority (CMA) ahead of its anticipated acquisition of Sainsbury’s pharmacy business.

Celesio AG operates 1,542 pharmacies across the UK through subsidiary Lloyds Pharmacy Limited, while Sainsbury’s owns 277 pharmacy stores.

Although the price of prescription medicines is regulated, the watchdog has identified 78 areas where customers may be affected by a loss of competition.

They include opening and waiting times, quality of advice, availability of medicines and additional services.

The CMA has also indicated that it has been unable to reach a positive conclusion as to whether the merger would lessen competition in other additional local areas.

The proposed deal will be referred for an in-depth investigation by an independent group of CMA panel members.

Sheldon Mills, CMA senior director of mergers, said: “The majority of consumers in the UK need to use pharmacies at one time or another and they evidently provide an important service.

“After the merger, Lloyds will no longer face competition in certain local areas from one of its rivals and following our initial investigation we are concerned that this might affect choice, quality and service for customers.

“We think a detailed investigation is needed to look at these concerns.”

The CMA is the UK’s primary competition and consumer authority.