A Bristol academy is to scan students' fingerprints to allow them to get their lunch.
The £20,000 scheme will be launched at the City Academy - the first to be built in the city - from September.
The school said the biometric system did not keep a photographic record, could not be used for police evidence and did not infringe civil liberties.
It also plans to introduce biometric controls to get into the school from next term and to control printing.
But Clare Stephenson, 43, who has a daughter in year 10 at the school, said she was outraged by the lack of discussion.
"I am staggered that no consultation has been made with parents about this and it is being pushed through in time for the new school term," she said.
She said she was angry that there would be no chance to discuss any concerns she had until a meeting in September.
"Does anyone think this is unnecessary and unwarranted?," she asked.
Students currently carry ID cards which can be used to pay for lunch.
The school said many were lost and were costing up to £6,000 a year to replace. The fingerprint scheme is aimed at supplementing these cards.
"It is such a good system, and there is no infringement of rights, that there was no need for consultation," a school spokeswoman said.
Vice principal Len Morphew added that the new system would be more efficient and would benefit the children.
'Infringement of liberty'
David Coulter, from the group Leave Them Kids Alone, said: "Without consent, this is an infringement of liberty.
"These systems store fingerprint templates, which are used by the police. It leaves children open to identity fraud later on."
The academy opened in 2003 and has more than 1,100 pupils aged between 11 and 18.
Among its visitors has been David Beckham, who turned up in March to teach youngsters football.