This is the Harrogate NHS Trust's advice for patients with appointments after global IT outage

The official Harrogate and District NHS Foundation Trust advice today is: “Overnight there has been a global software outage which is affecting some IT systems across sectors of the Trust. Please continue to attend any appointments as normal.”

As well as airports and supermarkets, some GP surgeries and pharmacies in other parts of England have said they are unable to book appointments or access patient’s prescriptions.

Royal Surrey NHS Foundation Trust has declared a critical incident after it was forced to contact patients who were due to have radiotherapy this morning to reschedule appointments.

Around two thirds of GP practices in Northern Ireland have been affected by the IT outage.

Some train services have also been affected - including operators such as Avanti West Coast, Great Western Railway, Southern and Thameslink.

North Yorkshire Council has said that some of its “frontline services” conducted digitally are currently affected by the IT failure, including car parking payments.

Crowdstrike, the US anti-virus company linked to the major global IT outage, has ruled out a cyberattack as the world struggles to cope with the tech 'disaster'.

In a statement on X, CEO George Kurtz said the outage was "not a security incident or cyberattack" but the fault of an IT update on Microsoft Windows.

He added that the company was now "actively working with customers" impacted by the worldwide IT crisis.