Patients at The Royal London and Mile End hospitals are facing cancelled appointments more than a week after their computer systems were hit by a cyber attack.

Barts Health NHS Trust, which runs the hospitals, was among around a fifth of the country’s trusts to be targeted on Friday, May 12.

A spokesman for the trust said that systems were gradually going back online, and that staff had only just regained access to emails.

He said: “We are very sorry for any delays and cancellations, and continue to ask patients and our partners (like GPs) to be patient while we work to resolve all the issues.

“For the moment we are asking the public to only attend A&E in an emergency, and to use other NHS services for urgent treatment if at all possible.

“However anyone who has a booked appointment for surgery or in an outpatients clinic should continue to attend unless we telephone you beforehand.”