The government has told head teachers to lighten up after one British school told children in the dinner queue that if they didn't give their fingerprints they wouldn't get any food.

The Department for Education and Skills said this week in a statement to the BBC Radio 4 Programme You and Yours that schools who refused school dinners to kids who won't scan their fingerprints might be in breach of the law, contrasting with the long-overdue guidance note it issued on school fingerprinting in the summer.

This draconian application of fingerprint technology at Morley High School, Leeds, had forced one parent to make her child packed lunches, since the school provided no alternative way for children to get their dinner.

John Townsley, head teacher of Morley High School, told You and Yours: "We have given parents an opt out. The opt out is that you don't have to have anything to do with the system whatsoever and that you then have the responsibility as a mum, dad or carer to provide a very healthy alternative to your child."

But the DfES said: "Schools have a legal duty to provide meals for pupils who want them. So telling concerned parents to provide pack lunches if they were unwilling to sign up to the fingerprint system, as Morley High was doing, might amount to a breach of the Education Act 2002."

However, the DfES said when it released the guidance in July that it supported schools' "freedom to run their own affairs", including whether they offered the children of dissenting parents an alternative way of getting their school dinners.