A spokesperson for St George’s, Epsom and St Helier Hospital Group (gesh) said: “We are aware of issues affecting all Microsoft systems and are working with our operational and IT teams to mitigate the impact where we can.

“Non-clinical systems like Outlook and SharePoint are working intermittently. All NHS organisations, including GP practices, are affected, meaning calls may be subject to long waits.

“Patients and staff should continue coming to our sites as normal.

“If you need urgent advice about your health, please use NHS 111 online.

“If you need help with your medications or a medical condition, but it is not urgent or life-threatening, please go to your local pharmacist.

“We will provide further updates when they are available.”

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