A million more blood donors are needed over the next five years - particularly those with the rarest blood types, NHS Blood and Transplant has said.
It said there is an urgent need for black African, black Caribbean and younger donors to come forward.
The number of active donors - those donating in the last 12 months - fell during the pandemic from nearly 808,000 in March 2020 to just over 750,000 in February 2021.
Although blood donation numbers have risen again since then, there are still almost 16,000 fewer active donors than before the pandemic.
The five-year Blood Service Strategy, published by NHS Blood and Transplant on Monday to mark the start of National Blood Week, also aims to double the number of donors with the rarest blood types and there will be a campaign to identify those with the most-needed blood types.
The service said there is a particular need for donors of black African and black Caribbean ethnicity to help treat people with sickle cell, the fastest growing genetic blood disorder in the UK, mainly affecting people of black heritage.
Sickle cell requires regular transfusions, most often with Ro blood. Some 55% of black blood donors have this subtype, compared to 2.4% of donors from other ethnicities.
In the next year alone, the strategy aims to recruit nearly 175,000 new donors, with the biggest target in London, where there are the most donor centres and high ethnic diversity means there is a particular demand.
Stephen Cornes, director of blood supply at NHS Blood and Transplant, said it can currently only meet around half the demand for Ro blood meaning many sickle cell patients receive less well-matched blood.
While this is clinically suitable, it can pose longer-term health risks to patients receiving regular donations, he said.
Mr Cornes said: “We urgently need new black African and black Caribbean donors to come forward and donate blood.”
He added: “In addition to the rarest blood types, we also need one million new donors over the next five years of all blood types. As the NHS treats more patients, we need to grow the total number of donors too.”