A former Supreme Court justice has said it is “high time to banish the long shadow” of the James Bulger case as he backed raising the age of criminal responsibility from 10 to 12.

Speaking at Westminster, Lord Brown of Eaton-under-Heywood warned criminalising young children was “deeply damaging”.

He supported a call in Parliament to raise the age at which youngsters can be prosecuted by fellow independent crossbencher and former High Court judge Baroness Butler-Sloss, who accused successive governments of ducking the issue because they were “afraid of what the public will say”.

Both peers referred to the shocking 1993 abduction and murder of two-year-old James Bulger in Liverpool by 10-year-olds Jon Venables and Robert Thompson.

Campaigners believe the horrific case, which rocked Merseyside and the nation, accounts for the reluctance of the authorities to increase the age of criminal responsibility.

They argue the country is out of step with the rest of Europe where the average age of criminal responsibility in many places is 14, and that research on child development supports an increase.

Speaking as peers continued their detailed scrutiny of the Police, Crime, Sentencing and Courts Bill, which contains wide-ranging measures aimed at overhauling the criminal justice system, Lord Brown said: “A 10-year-old’s mental capacities are not comparable to those of an older adolescent or adult.

“Criminalising these youngsters while they are still developing their identities and their character, growing socially and emotionally, is deeply damaging to their self-esteem and their future prospects.

“Brand a child 10 or 11 a criminal and that is how he will come to see and identify himself, and so in future he will behave.”

He added: “It is high time to banish the long shadow of the tragic Bulger case, which alas is still cast and obscures the realities the realities and common sense on this issue.”

Lady Butler-Sloss said: “We only have to look at what is happening across Europe.

“Scotland has raised the age to 12, the age of responsibility across Europe is either 12, or in more places it is 14. We remain at 10.

“I think it is probably because successive governments … are afraid of what the public will say.”

Recalling the “appalling” killing of James Bulger, Lady Butler-Sloss highlighted a coupon campaign by a newspaper at the time calling for his young attackers to be jailed for the rest of their lives, which was backed by 84,000 people.

She told peers: “The world has moved on, but the Government has not. The Government appears to have shut its ears to what is so blindingly obvious now.

“I would ask the Government just to open their ears a little, at least to look at the research and … do what is the obvious, which is to raise the age to 12.”

Accusing the Government of “moral cowardice” over the issue, Liberal Democrat Lord Marks of Henley-on-Thames said: “We need no review, now what we need is change.

“And we should do all we can to shame the other place (the Commons) into accepting the need for change.”

Labour shadow attorney general Lord Falconer of Thoroton backed increasing the age of criminal responsibility, but sounding a note of caution, he said: “What happened in the Bulger case was awful and it had an utterly legitimate effect on the Merseyside community.

“To try to dismiss that as being something ‘got up by the tabloids’ is in my respectful view to totally misunderstand the significance of the event.”

Referring to the comment made by Lord Brown, the Labour frontbencher said: “It is a long shadow, but the shadow is still there and it has to be dealt with.”

Responding, justice minister Lord Wolfson of Tredegar said the Government believed the current age of criminal responsibility was “appropriate” and allowed early intervention aimed at preventing further offending.

He added: “The horrific Bulger case has been raised by a number of peers.

“I remember that case clearly.

“I grew up in Liverpool.

“It shocked my native city to the core.

“But whether it’s the Bulger case or indeed any case involving children, even the most serious, there is a distinct and separate sentencing framework for children aged 10 to 17, which recognises that children have their own specific needs which require a different and more tailored approach.”