It fears that life-saving stocks will run low as regular givers find their time taken up with extra shopping, holidays and winter illness.
A lull in blood-giving is not unusual over the Christmas period. The service predicts that this year will be no exception.
Spokeswoman Liz Reynolds said: "The start of the new year coincides with the start of a traditionally busy time for hospitals and the need for blood in waiting list surgery."
Royal College of Nursing Secretary Christine Hancock is to give the service a boost on 6 January by giving her own blood at the union's London headquarters.
Ms Reynolds said: "We are delighted that the RCN is demonstrating its commitment to the need for blood. Nurses can save lives in more ways than one."
Ms Hancock said: "I hope by giving blood and encouraging staff here at the RCN to become regular donors, we can help top up current stocks and keep supplies healthy."
Background Briefings
Medical notes
A Christmas gift of blood
(04 Dec 98 | Health)
Pressure to ban UK blood
(26 Dec 98 | Health)
Blood donors take on transplant cancer
(14 Oct 98 | Health)
Giving blood - the secret of a long life
(14 Oct 98 | Health)
National Blood Service
Information about the Royal College of Nursing
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