Asda said it would accelerate its pharmacy opening programme to meet growing customer demand now that the Office of Fair Trading has recommended that the sector should be deregulated.

Asda's pharmacy director David Miles said: "The OFT's investigation of the pharmacy market confirms what our customers tell us - the current system denies them lower prices and access to pharmacies where they want them.

“We look forward to working with the DTI to make the case for fair competition and an end to the pharmacy closed shop."

Corporate affairs director at Tesco, Lucy Neville-Rolfe, said: "Where we have been able to operate pharmacies we consistently provide a first class, innovative , accessible and patient-focused service.

“We are keen extend this to more customers and more communities, and urge ministers to act quickly and positively on the OFT's recommendations."

A Sainsbury spokeswoman said it would be looking to double its number of pharmacies from its current 109.

Alistair Buxton of the Pharmaceutical Services Negotiating Committee said: "The OFT's blunderbuss approach is in direct conflict with existing health policy and planning objectives.

“The government's NHS plans include a series of major developments in community pharmacy, which will deliver enhanced services for patients. Those plans are based on the existing regulatory system — this report is an unwelcome distraction from that objective."