Three children died after a catalogue of errors by social workers,

In cases that echo the mistakes made during the short life of Baby P, the children were left in danger despite clear warning signs that they were at risk.

Repeated opportunities were missed to intervene to save the children, whose families were regularly visited by social workers, police and health workers.

Despite the blunders, no measures were taken to discipline any of the professionals involved.

Critics said the official reports into the cases, showed that the current child protection system was not working.

The three serious case reviews disclose:

A three-year-old girl died after taking her mother’s drugs. Just three weeks earlier social workers had considered — and then decided against — putting her into care

A 14-month-old baby was killed by a cocktail of drugs, months after social workers were warned her mother was taking crack cocaine and heroin

A baby of seven months died in bed with her mother, whose alcohol intake contributed to the death. Social workers who previously found the mother drunk in bed with the infant had asked her to sign an agreement to tackle her drinking, which she signed after consuming eight cans of beer.

In the case of the three-year-old, who was on the child protection register in Reading, just 25 of 84 attempts by social workers to visit her family were successful.

Despite her parents’ refusal to co-operate with social services, action was not taken to protect Trae-Bleu Layne, who died of a methadone overdose.

Even when her parents took her on a violent raid on local shops — which ended with a high-speed chase by police, who found the child in the back of a car next to drug-taking paraphernalia — authorities failed to step in to protect the infant.

The investigation demonstrates that the critical errors made by social services in the case of Baby P, whose abuse and death was not prevented by 60 visits from Haringey’s social workers, are being replicated across the country.

The cases raise fundamental questions about the competence of front line staff working in child protection, and the leadership of those running services.

Michael Gove, the shadow children’s secretary, described the cases as "appalling" evidence that the current child protection system had failed.

He said: "These particular cases seem quite appalling: they raise profound questions about the Government’s claim that we have got the right systems in place."

The NSPCC warned that countless more children would die as a result of abuse if lessons from investigations into the deaths were not heeded.

Wes Cuell, the charity’s director of children’s services, said: "There are many children who are alive today who will die in equally tragic circumstances if we continue to fail to learn the lessons from these cases."

He said serious case reviews by agencies responsible for child protection raised the same problems repeatedly: poor judgment by front line staff in health, police and social work; and weak supervision by managers in charge of child protection.