Radio Jackie’s John Beesley gives blood at Twickenham Donor Centre as a national alert is issued over blood shortages.

The NHS has issued a national alert over shortages of blood saying stocks are at ‘unprecedentedly low levels’.

It’s appealing for donors with O-negative and O-positive blood to come forward.

O-negative is described as the ‘universal’ blood type, because it can be given to all patients – but officials say they only have enough to last less than two days.