The UK’s largest NHS-approved online pharmacy has been instructed to act "urgently" by the industry watchdog following their dispensing chaos over Christmas.

Patients of Pharmacy2U were left in the lurch over the festive period after the company announced weeks of prescription delays.

The troubled pharmacy cited the transfer a new automated facility as the reason for the disruption that continues to leave patients without medication.

Pharmacy2U was previously fined £130,000 by the Information Commissioner's Office for unlawfully selling the personal details of 21,500 patients and customers to third party companies, including one that was under investigation for fraud.

Following the dispensing disruption the General Pharmaceutical Council (GPhC) and representatives from NHS England carried out a special inspection visit of the pharmacy's premises on 22 December 2015.

A spokesperson for the GPhC said: "Our inspection found that Pharmacy2U had failed to meet some of our standards for registered pharmacies.

"In particular, there was a failure to identify and manage the risks to patients receiving their medicines as a result of the recent move to new premises; and medicines and medical devices were not being supplied to some patients in a timely manner.

"We have required Pharmacy2U to urgently put in place an action plan outlining how improvements will be made so that patients receive their medicines in a timely manner going forward."

The GPhC will conduct a follow-up inspection to identify whether the necessary improvements have been made and the action plan has been implemented.