The only real defence against bio-terrorist attacks is to stop chemical and biological weapons being developed at all, doctors leaders have said.
A terrorist attack exercise is to be held soon
The British Medical Association told MPs on Wednesday that plans did need to be in place to cope with known biological agents.
But doctors cannot do anything when biological weapons are used where there is no known vaccine, said the BMA.
The association also demanded Home Secretary David Blunkett retract his suggestion earlier this week that there was no problem in people asking doctors for smallpox jabs.
If there was a problem, he would talk to the Health Secretary Alan Milburn, he said.
But in a rebuff to Mr Blunkett, Number 10 has now said the home secretary was merely "putting forward a point of view which the health secretary will look at".
There are no plans for a mass vaccination against smallpox, says the government.
Vivienne Nathanson, the BMA's head of science and ethics, said the Department of Health was "deeply concerned" by Mr Blunkett's remarks.
Conservative shadow health secretary Liam Fox said the public were entitled to know what precautions had been taken about smallpox.
Dr Fox said: "The smallpox vaccine is not available from GPs...
"The government admits that there are only 20 million doses of the vaccine available, roughly enough to cover one third of the population. "
It is essential to recognise that they are weapons of mass killing and incapacitation
Later, the Department of Health said it followed the advice of the World Health Organisation (WHO) about smallpox jabs.
The disease was declared eradicated in 1980, but the government held a "strategic resource for use in a national emergency which can
be disseminated quickly if required".
A spokesman added: "The vaccination is offered to a small cohort of key health care personnel across the UK in the first instance who will provide the risk response in the
event of a confirmed or suspected release of smallpox."
Mr Blunkett this week said the UK's contingency plans were being strengthened and would be tested at an exercise later this month.
But Dr Nathanson told the Commons science and technology committee her concerns about preparations.
She said: "GPs haven't been given a lot of
information and are not certain what their role would be (in the event of a
"They don't get information about how emergency services would cope, they
don't know what the local plans are.
"They are not confident that they would get
information very quickly about a specific threat."
She suggested local doctors heard more about the recent ricin scares from the BBC than anywhere else.
Dr Nathanson told the committee that "weapons of mass destruction" was not the right way to describe biological weapons.
"It is essential to recognise that they are weapons of mass killing and incapacitation," she said.
"These weapons do not destroy physical infrastructure but kill people, spread fear and interrupt the workings of society."
Dr Nathanson said it was important to understand why some states or terrorist groups use biological weapons.
"They do so precisely because physical infrastructure is unaffected and because they are cheap to produce and disperse.
"The only real defence against biological warfare is to prevent these weapons being produced in the first place."
Her warning of the dangers were echoed outside Parliament by John Eldridge, editor of Jane's Nuclear, Biological and Chemical Defence.
He suggested a "nightmare scenario" could be an attack involving a self-infected
terrorist who spread disease by mingling with crowds in towns or cities.
The Department of Health spokesman said GPs "probably did get
advice from the chief medical officer" about the
There were "robust contingency plans in place" for dealing with a bio-terrorist attack, added the spokesman.