The death of Khyra Ishaq shows that social workers on child protection cases should be paired up, according to Unison.
The comments were made after the serious case review, published in full this morning, concluded that the seven-year-old's death in 2008 was preventable and criticised Birmingham's children's services department, the police, health visitors and Ishaq's school.
"Unison has always said that child protection investigations should be undertaken by two social workers, one to concentrate on the adult and the other on the child," said Tony Rabaiotti, the trade union's head of local government.
"This is very relevant in Khyra's case, where her mother was accusing social workers of harassment."
Rabaiotti said Unison had warned Birmingham of shortcomings in its child protection systems over several years and continued to be frustrated at what he called the council's "inability to retain experienced social workers".
"Newly qualified workers arrive, stay for a few years, then take their expertise elsewhere," he said. "This puts more pressure on already overworked social workers."
Newly qualified social workers also needed to be mentored by more experienced colleagues, he added.
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