Leading doctors at Sutton, Epsom and St Helier hospitals are urging local people to help save a life by giving blood.
NHS Blood and Transplant are concerned after a dramatic decline in the number of donors signing up.
Dr James Marsh, the trust’s deputy medical director and renal consultant, is challenging local people to spare an hour of their time to donate blood.
He said: “At this time of year, people will be making plans for a wide variety of events, from weddings and birthdays to holidays and weekend breaks.
"Our challenge, although it may sound difficult is actually a very simple one - try and save a life. Donors help sick and injured people in local hospitals with each and every donation they make.
“We realise that people live extremely busy lives, but our patients still depend on blood transfusions to help improve their health, or even save their life.
“That’s why we’re asking that local people find time to donate blood – it shouldn’t take long to do, but your contribution could make a huge difference to a person in their hour of need.”
For more information about donating blood or to find more sessions near you, call 0300 123 23 23 or visit blood.co.uk