'Children should not be called criminals aged 10'

The poll comes as researchers found prison was unlikely to act as an effective deterrent for disadvantaged children with patterns of highly persistent offending - the group which makes up a high proportion of young people in custody.

But the Ministry of Justice confirmed it was not considering increasing the age of criminal responsibility and admitted that prosecuting children was "not always the most appropriate response to youth offending".

Nearly two-thirds (62%) of more than 2,000 adults surveyed for the Prison Reform Trust (PRT) did not support the current age limit, saying it should be raised to at least 12, according to the poll. And around the same proportion (63%) thought the minimum age of imprisonment for non-violent crime should be raised from 12 to at least 14.

The findings coincided with the publication of a joint report by the PRT and the Institute for Criminal Policy Research which showed many of the children being locked up were subject to high levels of disadvantage, relating to family and home life, as well as psycho-social and educational problems.

"The best way to reduce the use of imprisonment for children is to 'lengthen the road' down which children have to travel in the court process before they reach the sentence of last resort," the study's authors said.

It comes after children's charity Barnardo's warned at the weekend that criminalising young children increased their chances of reoffending.

Penelope Gibbs, director of the PRT's Out Of Trouble campaign which aims to reduce the number of children and young people imprisoned in the UK, said the report showed they were being punished twice.

"First, by having traumatic childhoods. Then, by being locked up, often for not very serious crimes," she said. "Prison is often seen as a deterrent, but for these young people it isn't. It is just the last in a long series of bad experiences in which family and state have failed to protect them from harm."

The Punishing Disadvantage report, which studied 300 children involved in the 6,000 cases of youth custody in the second half of 2008, found about three in four had absent fathers, around half lived in a deprived household or unsuitable accommodation, and just under half had run away or absconded at some point in their lives. It also found two in every five had been on the child protection register, or had experienced abuse or neglect.