The father of James Bulger was today asking the High Court in London to block the release of his son's killers.
He will claim the Lord Chief Justice Lord Woolf did not know the full facts when he effectively ended the tariff which sets the minimum sentence they must serve.
Robert Thompson and Jon Venables, now both 18, hope to win parole after Lord Woolf said: "Neither has shown any aggression or propensity for violence during his period of detention."
Lord Woolf made the assertion when he recommended last October their tariffs be cut to eight years. This would make the two eligible for early release although the Parole Board will make the final decision.
But today on the steps of the Royal Courts of Justice in London solicitor Mr Robin Makin - representing the toddler's father Mr Ralph Bulger - said the senior judge was "plainly wrong" and the whole case must now be reconsidered.
Mr Makin, speaking before the start of Mr Bulger's application for judicial review, claimed there had been allegations of two incidents of violence involving Thompson.
Lawyers for Mr Bulger (34) will also argue at today's hearing the senior judge put rehabilitation before punishment and deterrence in a way which was so flawed that his recommendation cannot be allowed to stand.
The two were aged 10 when they abducted and tortured the two-year-old child on a railway line in Liverpool in 1993. PA