Schools have been given the go-ahead to take fingerprints from children as young as five – without asking their parents first.
Ministers issued guidance allowing heads to collect pupils’ biometric data to use when taking the register, paying for lunch or using the library.
Schools can also take retina and iris scans and record children’s voices, face shapes, hand measurements, handwriting and typing patterns.
Civil liberties campaigners are concerned that the data could be given to police or the Government without parents’ knowledge – or stolen by identity thieves.
The advice, contained in official guidance published, has infuriated parents’ groups.
Whitehall officials insisted the data is not stored as fingerprints but unique number streams derived from the prints, rendering it useless to anyone except the school using the system.
However the claims were disputed by campaigners who oppose the use of biometric data in schools. They also said that school computers are not secure enough to keep the data safe from hackers.
An investigation earlier this year found that 285 schools have already introduced fingerprint scanners.
They are used for a range of purposes including tracking children during the day to ensure they are not playing truant.
However, less than a fifth had first sought parental consent, according to a survey by the Liberal Democrats.
LibDem MP Greg Mulholland said: “It is highly disappointing and unsatisfactory that there remains no legal requirement for parental consent before a child’s biometric data is collected.
“This is unacceptable. A school would never dream of taking children on a school trip without consent, but collecting their fingerprints is not subject to the same safeguards.”
Nick Gibb, Tory schools spokesman, called the guidance “disappointing”.
He said: “It is very weak as it neither requires schools to seek parental consent nor recognises the serious issues at stake with schools fingerprinting children simply for administrative convenience.”
David Coulter, from the pressure group Leave Them Kids Alone, added that allowing schools to take children’s fingerprints without consent was an “infringement of liberty”.
He said: “These systems store fingerprint templates, which are used by the police. It leaves children open to identity fraud later on.”
Polls by lobby groups suggest as many as 3,500 schools have bought the necessary equipment.
Many heads are said to have been waiting for the official guidance before bringing in the systems, fearing they could be breaching data protection law.
This states that while schools should notify parents they are taking biometric data, they do not have to seek formal consent.
And if pupils are old enough – thought to be around the age of 12 – do not even have to notify parents. They can comply with the law simply by informing the child.
Campaigners wanted ministers to force schools to ensure they had written permission from parents before taking children’s fingerprints.
But the guidance merely told heads it was “good practice” to be “clear and open” when introducing biometric technology.
It advises schools to make contingency plans if parents object, for example by keeping a smartcard service running alongside fingerprint scanners.
However there is no requirement for them to do this.
Parents’ only option if they are unhappy with the changes is to complain to the Information Commissioner.
Schools Minister Jim Knight insisted: “Biometric data is increasingly being used in schools. This guidance advises schools to fully involve parents in any decision to introduce this new technology.
“I want parents to be fully engaged with every aspect of their children’s education – this is at the heart of today’s guidance.
“I back every headteacher’s right and professional judgment to choose technology to improve their day-to-day running – but it is plain common sense for them to talk to parents about this.”
The guidance, issued by the Government funded British Education Communications and Technology Agency, known as Becta, said schools must not pass on the information to outside bodies and should destroy it as soon as the pupil leaves.
However Liberty, the civil rights group, said: “The police have the right to get into any database, private or public.”