NHS England and pharmacies warned of delays and slower than usual services today, as the health sector continues to recover from Friday’s global IT outage.

The health service said patients with appointments this week should continue to attend unless told not to, while the chairman of the National Pharmacy Association has asked people to be patient as pharmacists work to catch up on the backlog of prescriptions.

It comes after the British Medical Association (BMA) warned on Sunday that normal GP service “cannot be resumed immediately” after the outage caused a “considerable backlog.”

The doctors’ trade union said GPs will need time to catch up from lost work over the weekend, adding that NHS England should make clear to patients this is the case.

The BMA said its GP committee will continue to talk to NHS England and patient record system supplier Emis to secure a “better system of IT back-up” to ensure the “disaster” is not repeated.

A flawed update rolled out by cybersecurity firm CrowdStrike knocked many services offline around the world on Friday, causing flight and train cancellations and crippling some healthcare systems.