'Raise age of criminal responsibility if powers are devolved'
The age of criminal responsibility should be raised from 10 to 12 to help prevent reoffending, a Plaid Cymru assembly member has said.
Steffan Lewis said such a move could be a benefit of devolving justice powers - which are currently run in Westminster - to Wales.
David Davies, Tory MP for Monmouth, criticised the idea.
He said serious offences committed by 10 and 11-year-olds should be dealt with by the criminal justice system.
Mr Lewis, a South Wales East AM and Plaid's criminal justice spokesman, said: "Serious offences committed by children are extremely rare, but can, of course, be devastating for the victims.
"The focus should always be on the safety and security of our communities, but the answer is not criminalising children at a young age.
"Through early intervention and rehabilitation we can stop children being drawn into a lifetime of reoffending."
He said the UN Committee on the Rights of the Child had "made it clear that a minimum age of criminal responsibility below the age of 12 years is not acceptable".
"The law must be changed to be in line with international guidelines as soon as possible," he said, saying he would back a consultation on increasing the age beyond 12.
"A public debate is needed, drawing on all available evidence, on what age it is appropriate to hold children fully criminally responsible for their actions," Mr Lewis said.
Calling for a focus on children's wellbeing, he said: "With justice devolved we could do so and meet international standards."
Proposals for the devolution of youth justice were made by the Silk Commission, which looked at the future of the devolution settlement in Wales in 2014.
But the idea was not supported by the UK government and did not make it to the Wales Bill on further devolution, currently making its way through Parliament.
Conservative MP Mr Davies said: "First of all I wouldn't want to see youth justice being devolved, as we have already got problems with cross border services where we have got different policies in place in England and Wales.
"If people commit offences in one jurisdiction and live in another it is likely to cause all sorts of legal problems."
He also said he would "not want to raise the age of criminal responsibility" and serious offences carried out by children aged 10 and 11 "need to go through the criminal justice system".
"The boys that killed James Bulger wouldn't have been prosecuted if the age of criminal responsibility had been 12," he added.
Robert Thompson and Jon Venables were aged 10 at the time of the murder in 1993.
It is understood the UK government has no current plans to alter the age of criminal responsibility.
The Ministry of Justice declined a request for comment.