It could make the time-honoured tradition of taking the school register a thing of the past.

Cutting-edge cameras are being used to scan children’s faces as they enter school.

The face-recognition technology makes sure they have turned up, records whether they were on time or late and keeps an accurate roll call.

It can also deliver messages to pupils as they sign in. Ten schools have started using the system, which is likely to be introduced elsewhere if considered a success.

But privacy campaigners reacted angrily yesterday, warning that the technology was another ‘encroachment on civil liberties’. Britons are already subjected to the greatest level of electronic surveillance in the world, with our movements said to be recorded in some way about 3,000 times a week.

Facial recognition systems are in use in airports to catch those using fake passports.

The faceREGISTER systems that are being installed in schools take 3D digital images of faces and infra-red scans.

Pupils must face a box which is the size of an A3 piece of paper while their image is taken.

They then punch in their four-digit pin on a number pad to confirm their identity.

The technology, made by Northamptonshire firm Aurora Computer Services, is said to be so accurate that there is no chance of pupils signing in for their friends.

The system is being used in schools in Northamptonshire, Hertfordshire and Cambridgeshire. Sir Christopher Hatton School, a comprehensive in Wellingborough, Northamptonshire, started testing it on A-level pupils last month.

The technology has been installed in reception and the sixth-form block at a cost of £9,000.

Head of sixth form Kelli Foster said: ‘The technology is just incredible. Before, each pupil had to sign in and out of the reception by filling in a form but now it takes under ten seconds to gather so much more information.’

But Big Brother Watch campaign director Daniel Hamilton said: ‘This is another worrying development in the expansion of the surveillance state.

‘There is no need for schools to hold such sensitive information about their pupils. Such systems have limited benefits yet are wide open to abuse – from the risk of data theft to misuse by unscrupulous individuals.

‘Rather than spend money on gimmicks like this, schools should focus on educating their pupils. Both parents and pupils should resist this encroachment on civil liberties.’