There has been a division of opinion over the 20-year prison sentence handed to cold murderer who stabbed his teacher to death in front of a class of horrified pupils.

Cornick (left) stabbed teacher Ann Maguire (right) to death in April

Cornick (left) stabbed teacher Ann Maguire (right) to death in April

Will Cornick stabbed his teacher Ann Maguire seven times as she taught a Spanish class at Corpus Christi Catholic College in Leeds in April.

Cornick carried out his earlier boast to friends that he was going to kill Mrs Maguire. He also claimed he would murder other teachers, including a female member of staff who was pregnant woman “so as to kill her unborn child.”

After Mrs Maguire’s brutal slaying, the remorseless teenager said he “couldn’t give a sh**” and that “everything I’ve done is fine and dandy.”

During psychiatric assessments, Cornick told doctors: “I said I was going to do other stuff but I never got the chance, other murders. It was a triple homicide.”

Cornick was 15 at the time of the murder; during sentencing, Mr Justice Coulson told him he might never be released from prison and sentenced him for 20 years.

However, Penelope Gibbs, the chairman of the Standing Committee for Youth Justice (SCYJ) said today that Cornick’s sentence was too long.

Speaking on the Today programme on BBC Radio 4, Ms Gibbs said: “We are out of line with the whole of western Europe. There are no other countries within western Europe which give children – and this boy is seen as a child under the UN Convention on the Rights of the Child and is in the youth justice system – a life sentence.

“Punishment is also incredibly important, particularly for the victims and families, but the fact is, how many years do we need for punishment? We have given him a sentence which is more than his own lifetime.”

Ms Gibbs went on: “He was 15 when he did this crime and we would say that you don’t need that long to punish. What is crucial is that when he is released he is assessed as no longer being of danger to himself and others and thus we would all be safer. But there is no evidence that that takes 20 years and we’ve looked and we think that this is the longest sentence given to a child in at least 10 years … I’m not going to tell you exactly what the right sentence would have been, but 20 years and a life sentence is too long.

“There are very good prisons, there is a prison called Grendon which is a therapeutic community, and prisoners go there for a few years and it has great results. The question is – safer society, yes; punishment, yes – but does it need to be more than his lifetime?”