The Government has faced growing demands to release more information about Jon Venables's return to prison - led by victims' rights champion Helen Newlove.
Mrs Newlove, whose husband Garry was kicked to death by a gang of yobs outside their home in Warrington in 2007, said it was cruel not to tell James Bulger's parents the full details.
She urged the Prime Minister to think again after he and Justice Secretary Jack Straw declared the new allegations faced by the little boy's murderer must remain secret.
Mrs Newlove said: "It is another case of the victims not coming into it and the criminals being protected.
"James's poor mother and father have to relive what's happened every day.
"What Jack Straw has said is ludicrous. Venables has breached his parole and should be staying in jail.
"Venables and Thompson have been given everything on a plate and now we're not even allowed to know the circumstances surrounding this - it is a disgrace.
Venables, 27, was taken back to prison more than a week ago after reportedly fighting with a work colleague and developing a drug problem.
In 1993 he and Robert Thompson, both just 10 at the time, led two-year-old James from a Liverpool shopping centre on a two-mile walk to his death.
They battered the little boy and left his body on a railway track for a train to cut it in two.
