Sir Liam Donaldson, UK's chief medical officer, has attacked the health profession for complacency in its preparations for a lethal flu pandemic that he says is now a "biological inevitability".
Last week Donaldson called together 30 public health leaders, including the heads of the royal colleges, to emphasize that the disease could kill between 50,000 and 750,000 people and should not be treated as a joke.
He is planning to issue a "protect and survive" leaflet to every household in England and Wales and has instructed all hospitals, doctors' practices and National Health Service trusts to inform him of contingency plans for coping with mass casualties.
Donaldson fears that the current level of precautions could lead to a lethal strain of flu arriving unnoticed.
"Many doctors think, 'Flu is flu, we see it every winter'," Donaldson said. "We have got to get the message through that this is going to be much more serious. "I can't give a likelihood of it starting this year, next year or in five years, but it will come. There is a biological inevitability and we've got to be prepared for it."
Donaldson said he was dismayed after hearing that some hospitals were "full of dead parrot jokes and people (don't) believe this is actually going to happen".
The first victim of bird flu in Britain was a parrot infected with the H5N1 strain that died in quarantine at Heathrow last month. This strain has devastated poultry flocks in the Far East over the past eight years and killed 62 people, raising fears that the world may be on the brink of a lethal mutation of the virus capable of sparking a human pandemic.
Donaldson believes that the predicted emergence of the killer strain will be the biggest test of his career and the worst epidemic to face the NHS. "We can't be alarmist, but we have to take it seriously and we have to prepare," he said.
In addition to awarding a contract for 14.5m doses of the anti-viral drug Tamiflu, so far the only one available, Donaldson is supervising the protect and survive leaflets, similar to those produced when the nation believed itself to be under threat of nuclear attack.
Experts fear the H5N1 strain of avian influenza, which has killed millions of birds in Asia directly and through culling, could mutate to allow human-to-human transmission. So far it has killed 62 people but has infected only those who work closely with poultry.