Thousands of kind-hearted Brits have rushed to donate blood to the NHS after an amber alert over critically low stocks.
Most appointments to donate blood this week are now fully booked but the NHS is still appealing for people with O negative or O positive blood to come forward for priority booking.
The first ever amber alert occurred because supplies of vital O negative blood - which can be given to most - are below two days.
NHS Blood and Transplant (NHSBT) aims to always have six days' supply.
The Mirror has launched a campaign to help recruit the tens of thousands of regular blood donors it is short as the service recovers from the Covid-19 pandemic.
More than 10,000 appointments to donate blood over the next few weeks were booked in the past 24 hours, NHSBT said.
On the blood website, 100,000 people queued to offer help, with some waiting up to an hour to book.
More than 166,000 people also visited the website overall, while 7,500 people registered as new donors yesterday - the highest daily spike in new registrations in 20 years.
Staff shortages have meant NHS Blood and Transplant (NHSBT) has been unable to put on more donation sessions.
An NHSBT spokeswoman said: “This is an amazing response from the public and we have been reminded in the last 24 hours of the incredible goodwill and spirit of the public towards helping patients in times of great difficulty.
“Staffing and appointment availability continues to be our biggest challenge and the amber alert will remain in place for at least the next four weeks, where unfortunately limited appointment availability to donate will be commonplace due to staffing levels.
“We know this can be frustrating for donors who want to book an appointment right now to help.
“Please be assured that we are doing our utmost to prioritise appointments for blood types most in demand right now.”
Hospitals have been told to implement plans to protect their stocks, and this could see non-urgent operations requiring blood being cancelled or postponed.
NHSBT said it was urging donors to keep checking for appointments in the future, including in November and December, especially at permanent donor centres in towns and cities which have extended hours and greater capacity.
People can visit blood.co.uk or use the blood app to check if there are appointments nearby.
O positive or O negative donors are being asked to call 0300 123 23 23 for a priority appointment.