The NHS website crashed as people over the age of 45 were told they can book their first Covid jab in England.

Users attempting to book their vaccine were shown an error message with the site experiencing “technical difficulties”.

A message on the website read: "The NHS website is currently experiencing technical difficulties.

"We are working to resolve these issues. Thank you for your patience."

On social media, other users reported a message that said: "You are in a queue. Lots of people trying to book an appointment."

The technical glitch occurred just moments after people over the age of 45 were told they can start booking their vaccine appointments.

All adults in the UK aged over 50 have now been offered a first dose of a coronavirus vaccine, paving the way for the next phase of the rollout.

Boris Johnson hailed another “hugely significant milestone” in the programme to protect the country against the disease.

It means the Government has met its target of offering the jab to all of its top nine priority groups, including the clinically vulnerable and health and social care workers, three days ahead of its target date of April 15.

In a statement, Mr Johnson said that they remained on course to offer a first jab to all adults in the UK by the end of July.

“We have now passed another hugely significant milestone in our vaccine programme by offering jabs to everyone in the nine highest risk groups,” he said.

“That means more than 32 million people have been given the precious protection vaccines provide against Covid 19.

“I want to thank everyone involved in the vaccine rollout which has already saved many thousands of lives.

“We will now move forward with completing essential second doses and making progress towards our target of offering all adults a vaccine by the end of July.”

NHS England chief executive Sir Simon Stevens said 19 out of 20 over 50s had now received a first jab.

“Thanks to our NHS nurses, doctors, pharmacists, operational managers and thousands of other staff and volunteers, the NHS Covid vaccination programme is without a doubt the most successful in our history,” he said.

“It’s one of our tickets out of this pandemic and offers real hope for the future.”