A Google outage has caused hundreds of websites and apps to crash, leaving Britons unable to access NHS services and their online bank accounts.

The tech firm's Cloud service, which provides data storage and processing power for both users and services, began experiencing problems at around 7am today and affected its europe-west2 data centre in London.

Services such as NHS England, Royal Mail and Rightmove went down as a result of the outage, which Google said was due to a power outage.

And several banking apps including Halifax, Lloyds, Revolut and HSBC also experienced issues. 

The outage also affected legal proceedings, with the Criminal Bar Association (CBA) saying that it had 'hampered' barristers' attempts to clear the backlog in the courts. 

The Russell Brand trial was also affected by the disruption, with some watching the proceedings online unable to access the footage. 

In a statement made earlier today, Google claimed that the outage was triggered by a 'a power event'.

However, the tech firm says it has now resolved the issue, writing in a statement that the problem 'has been mitigated for most of the customers and it is believed to be affecting currently a very small number of customers'.

At the time of the outage Google issued an apology to anyone affected by the disruption and thanked users for their 'patience while we're working on resolving the issue'.

In a post on X, the CBA wrote: 'Cloud Video Platform (CVP) is down across large parts of England and Wales since 10am.

'Many of us today, both as prosecution and defence counsel, can not proceed with trials and other hearings. Our work to clear backlogs is hampered.'

Likewise, HM Courts and Tribunals Service wrote on X: 'We're aware of an issue affecting Cloud Video Platform, used for some remote hearings.' 

Some Britons were also unable to use their online banking services, leaving them unable to send or receive payments.

By 9.00am, online tracker Down Detector showed 480 user-submitted reports of disruption affecting the Lloyds Bank app and website.

Of those affected customers, 36 per cent said they were unable to log in, 31 per cent said they could not use online banking and a further 25 per cent said they could not use the app. 

Halifax Bank wrote on X that the company was 'aware some customers are having issues with our app and online'.

The budgeting app Emma reassured customers on social media that the outage was 'not a security issue'.

The company wrote: 'Emma is currently down due to a Google Cloud outage affecting services in London since 7am.'

The banking app Revolut also appeared to be partially affected, with customers worldwide unable to open the app, send money, or even make card payments.

On X, one frustrated customer complained: 'This morning: Can't buy breakfast. Car is stuck in a paid car park. Can't pay for taxi or scooter as backup. Probably should be carrying some cash.' 

'Nothing like being stuck in the middle of a city in Japan, unable to pay for literally anything and having to cancel my beauty appointments because my bank @Revolut is having a massive outage,' wrote another.

While one customer said: 'I'm at a petrol station in Australia. Can't pay for my fuel that I just put in my car.. so I'm just standing in the petrol station highly embarrassed and can't get home to my kids.'

According to Down Detector, issues began around 8.00am this morning and quickly escalated as users shared hundreds of outage reports.

By 8.02am, Revolut had more than 1,458 reports of service disruption.

Of those, 62 per cent of customers said they were having problems with the app, 22 per cent with funds transfer, and 9 per cent with mobile banking.

In a post shared on X earlier today, Revolut says: 'We are currently experiencing a service disruption affecting multiple services. We can confirm that all our customers' money and data are safe. 

'We've been working to fix the issue since it was identified this morning and apologise to anyone affected and for any inconvenience caused.'

Marijus Briedis, chief technology officer at NordVPN, told the Daily Mail: 'When a cloud outage leaves people unable to make payments or access everyday services, it exposes how much we depend on infrastructure we never see.

'For everyday Google users, this dependence can mean several services they rely on suddenly being unavailable at the same time. Someone unable to pay through one banking app may find their alternative is affected too.' 

Mr Briedis adds that the enormous scope of Google's cloud computing services means that outages might affect businesses whose customers have no idea they depend on the company at all.

Cloud computing involves companies paying providers such as Google and Amazon to handle their data management, storage and networking at large data centres.

These services are typically far cheaper for companies than managing their own servers, and typically extremely reliable.

However, when a major provider does experience a problem, it can have cascading effects due to the number of companies affected.

This outage is the latest in a string of serious service disruptions that have affected cloud services over the last few years. 

Last year, both Microsoft Azure and Amazon Web Services saw major outages that brought 'half the internet' to a standstill.

Together, Amazon and Microsoft's vast data centres, known as 'hyperscalers', host more than 60 per cent of the world's cloud services.