Schools might not even have to inform parents as long as the fingerprinting system doesn't offend the DPA and children have the capacity to decide for themselves, he said.
But who gets to say whether a particular child is capable of consenting to their biometrics being taken - whether a child understands the implications of what they are being asked to do, or whether the decision should be deferred to the parent?
"That's for the school to decide," said Smith.
But campaigners against fingerprinting, such as www.leavethemkidsalone.com, don't trust schools to make that decision.
"There will always be a question in a school environment about whether consent is given," agreed Smith. "The teacher/pupil relationship makes it difficult to obtain freely given consent".
Moreover, in practice the decision is not likely to be given to individual children but presented to the class as a whole. A judgement, Smith conceded, was likely be made about the ability of a class as a whole to make a judgement.
So there might be room for concerned parents to manoeuvre: they might show that consent was not fairly sought or given, with children being given unbiased information to aid their decision. More broadly, they might argue that the decision about whether to hand over fingerprints and other biometrics goes beyond their ability to comprehend.
"[The guidance] will address consent, but it will make clear that what is essential is, [if] what's done is reasonable and proportionate, then consent wouldn't be required," said Smith.
The DPA has scope only to see that fingerprinting is done for a specific purpose, that only necessary data is collected, kept for the necessary time, and used for the allotted purpose by only the allotted people, as long as it is stored securely and not shared willy nilly.
Asked to clarify the legal basis on which its claim was made, the DfES conceded that schools had to ensure their fingerprinting schemes were compliant with the Data Protection Act and the Human Rights Act.
DoES said: "[Schools] should also inform parents and get consent unless the child is of 'sufficient maturity that s/he can give consent her/himself'."
According to Anne Marie Hutchinson OBE, head of the Children Department at Dawson Cornwell law firm, the applicable areas of the Human Rights Act (and Children's Act) legislation concur with the ICO's interpretation of the Data Protection Act: children below the age of 16 can consent if they can demonstrate they have the legal capacity - the nous - to do so; otherwise, parents decide. That will vary child by child and according to decision they are being asked to make.
Unless they can find a way of bringing a case on broad principles, parents who dislike a school fingerprinting their kids without parental consent will have to fight on a case by case basis, based on the legal capacity of their child or the approach of the school.
Yet, as biometrics have already made such rapid encroachments into Britain's schools, it is likely that by the time any such cases get heard, fingerprinting will already be a daily routine for many British children. ®