The public must wake up to the hidden dangers of ID cards, the chairman of an influential committee has warned.
Identity cards could hold sensitive personal information
The Earl of Selborne, chair of the Royal Society's science in society committee said the public is "sleepwalking" into its future.
With advances in technology ID cards can carry sensitive personal information such as medical records.
This could be both advantageous and dangerous, he told BBC News Online.
Lack of debate
"Putting specific medical information saying someone is a diabetic or is allergic to peanuts could be useful in a medical emergency.
"But what if the ID cards also held data about our genetic disposition to specific diseases or revealed information about our lifestyles, such as whether we are overweight or how much we drink," he said.
"This will be technologically possible in the future, so we need to ask ourselves if it's really desirable."
Lord Selborne called for the public to be better informed about ID cards.
Quick and cheap
His comments come ahead of next week's ID card trials involving thousands of volunteers.
"There has been a lack of public debate and there is a very real danger we are sleepwalking into our future," he said.
"The government needs to act in everybody's interests here.
Before we know it we may find our privacy has been encroached."
"On the whole I am in favour of the introduction of ID cards as a quick and cheap method of people identifying themselves.
"But before we agree to sharing sensitive personal information such as medical records we should be better informed," he said.