Blood donated from across the south-east will be processed and tested in Colindale as part of National Blood Service plans to centralise its operations.

It was previously thought that the Blood Transfusion Centre in Colindale Avenue would become one of only three "blood supercentres" in the country after the NBS published its five-year strategy in 2006.

However, concerns about the geographical spread of the centres and the availability of blood prompted a review, made public at the end of last month. The latest strategy comprises six centres, still a reduction from the current number of 14.

Lynda Hamlyn, chief executive of NHS Blood and Transplant, said the move has been prompted by the need for the service to become more efficient.

She said: We are currently working at 40 per cent excess capacity in our blood processing services and 35 per cent in our blood testing services.

"The changes set out in the review will enable us to be more productive, while giving us the necessary flexibility to meet clinical and safety requirements now and in the future."

Operations at other processing and testing sites will be scaled back over the next three years as the Colindale site increases its workload.

The case for Colindale as one of the "supercentres" was made by Hendon MP Andrew Dismore, who lobbied against the prospect of job losses in Colindale when it appeared that the site would not be one of those to make the cut.

It is not thought that the changes will lead to increased investment or more jobs on the site and elsewhere up to 600 people could lose their jobs. The trade union Unite has refused to rule out industrial action.