The Irish Blood Transfusion Service (IBTS) has launched a new campaign to attract more donors.
The move comes after fears the service might be unable to cope with a major emergency in the near future.
Publicising the "Blood Awareness Week" campaign, Fine Gael health spokesman Mr Gay Mitchell said stocks were running short during the summer months and that the supplies were further hit when 12,000 people were banned amid fears of transmitting variant CJD.
The IBTS revealed some stocks of blood types were now down 25 per cent below minimum levels.
The universal blood type O negative, which can be given to someone of any blood type in an emergency, is 25 per cent below the required stocks level, figures published on the IBTS website reveal.
Blood types A negative and AB negative were also significantly below the required level.
At the moment, 100,000 people give blood, which is used to treat nearly four million patients, annually.
additional reporting PA