The seasonal dip in donations has coincided with higher than normal levels of flu-like illnesses preventing donors from giving blood. As a result the National Transfusion Service has less than 18,000 units when 25,000 to 30,000 is normal.
Urging donors to keep their appointments, Mr Sackville said: 'We have a particularly serious problem with Group 'O'. This is always in great demand because almost half the population is Group 'O'. It can also be given to other groups when there is no time to check their blood group, in an emergency.'
Sue Cunningham, of the National Blood Authority, which organises the transfusion service, said that about 10,000 450ml donations a day were needed.
New blood donors can enrol on Freephone 0800 300333.