Hundreds of NHS websites across England and Wales have crashed after their online provider entered administration.

Websites of GPs that use the services of Silicon Practice, which claims online that more than 1,000 practices are reliant upon it, are unavailable.

Patients visiting sites for surgeries such as Millwood Medical Practice in Great Yarmouth and Southgate Surgery in north London now only receive automated error messages reading ‘Bad Gateway’.

A notice of administration was filed by Silicon’s parent company, Schappit Ltd, earlier this month, after facing financial difficulties.

NHS England said less than 10 per cent of its more than 6,000 general practices had been affected.

In a statement on social media, School Lane Surgery in Thetford said: “Unfortunately, the disruption to our website and online forms is going to last longer than we had hoped. This is part of a national issue affecting multiple GP surgeries, and we do not yet have a confirmed date for restoring access.

“We are exploring alternative options for our website and online forms while we await further updates from NHS England.

“We will share more information as soon as we can confirm the next steps.

“School Lane Surgery remains open as usual. If you need help from us, please call the surgery.

“Our phone lines are busier than usual, so please expect longer waiting times. We have arranged for as many team members as possible to answer calls, and everyone is working hard to help you as quickly as they can.”

Swansea Bay University Health Board said it knew of three practice websites that had ceased to operate, while the West and North London Integrated Care Board said practices using Silicon’s services “are advised to inform patients that they will not have access to online consultation requests and provide alternate approaches to contact the practice for clinical support until an alternative online consultation provider is in place”.

Silicon Practice ran the digital tool FootFall, which it advertised as reducing patient phone calls to practices by 30 per cent.

It said FootFall worked to “free your reception team from routine admin and manage demand more efficiently. Proven in 1,000+ practices across the UK”.

NHS England said it had contacted practices to ensure the impact on patients was minimal.

A spokesperson said: "While the majority of GP practice websites are running as normal, some practices which use Silicon Practice will be affected by the company going into administration.

"If your GP practice website is unavailable and you need help, you should contact your practice by phone or in person as usual."