The NHS website appears to have been hit by a glitch as thousands of 25 to 29-year-olds try to book their vaccine appointments.
Many within the new, lowered age range have been told they are “not eligible” for the jab, while others have reported virtual queues of almost 12,000 people.
Others have reportedly received a message stating “you are now in a queue, lots of people are trying to book an appointment”, without receiving any suggestion of their position or how long they will have to wait.
It comes after Health Secretary Matt Hancock announced in the Commons on Monday that those aged 25 to 29 would be able to book their vaccine appointments from Tuesday morning.
“From this week we will start offering vaccinations to people under 30, bringing us ever closer to the goal of offering a vaccine to all adults in the UK by the end of next month.
“From tomorrow morning, we will open up vaccination to people aged 25 to 29,” Mr Hancock said in a statement to MPs.