Leeds City Council has promised it will never again place a child in the care of a convicted paedophile, after an appalling failure within its social services.

The case of ‘Ruby’ (not her real name) – a vulnerable Leeds girl who was  sexually abused over several years by her legal guardian – made national headlines in January, when a safeguarding review highlighting the case was published.

A man with a history of child sex offences had been given custody of Ruby by a family court on the advice of the local authority, despite them knowing of his previous convictions.

The case was solemnly debated by councillors across the city at Civic Hall on Wednesday.

All parties voted in favour of a white paper, which included the statement: “This council believes there should be no circumstances in which convicted child sex offenders are given custody of a child”.

The debate was triggered by a motion from Opposition Conservative councillor Ryan Stephenson, who has been one of the most outspoken critics of the Labour administration’s handling of the case.

Councillor Stephenson told the meeting that putting the motion forward had been a last resort.

“The abuse inflicted on Ruby was both predictable and preventable,” he told an unusually silent debating chamber.

“It’s a deeply troubling fact that’s kept me awake at night and should weigh on the minds of all of us in this council chamber as corporate parents.

“A number of us have been pursuing the lessons and responses from this case for over a year now. It didn’t need to come before full council today.

“It’s only doing so because there’s been a co-ordinated attempt to block democratic scrutiny.”

Coun Stephenson said he hoped the principles of the motion would soon be adopted nationally and enshrined in ‘Ruby’s Law’.

The review of the case told how social workers had relied on “outdated assessments”, which suggested Ruby’s guardian did not pose a threat to children.

The local authority has never explained why these old assessments were used, instead of carrying out new ones.

The council has also been roundly condemned for its initial decision that the abuse of Ruby did not reach a “serious harm” threshold, and therefore did not need to be referred to a national safeguarding panel.

That decision was later reversed.

Councillor Fiona Venner, the administration’s executive member for children’s social care, said the case had “shocked and saddened” her.

But she insisted the council and its partners had an “open and reflective culture”.

“In their recent visit Ofsted, didn’t find any serious issues of concern with the safeguarding of children in Leeds,” Councillor Venner said.

“This Labour council takes our responsibility of safeguarding children extremely seriously and we are never complacent.”

Council leader James Lewis added: “The heartbreaking case of Ruby and the abuse she experienced is abhorrent.

“Cases like this can’t fail to sharpen our determination to double down on the protection of children and young people.”

Ofsted graded Leeds’ children’s services as ‘outstanding’ for a second consecutive time last May. That was after Ruby’s abuse had come to the attention of the authorities, but before the case had come to light publicly.

Council sources have insisted Ofsted were fully aware of the case themselves before it delivered its judgment.

But Conservative councillor Dan Cohen told the meeting the Ofsted rating was “not a shield to deflect legitimate criticism”.

His party leader, Councillor Andrew Carter, claimed he’d been “seriously misled” by the administration when he first heard about the case.

In a withering speech, he accused senior council figures of being “more concerned with reputation, than what had gone wrong in a very clearly tragic case”.

He said: “It’s damaged my faith in the operations of this council very badly indeed.

“These failings must never happen again, if we can do anything about it at all.”

A report detailing the council’s next steps, and how it will ensure paedophiles are no longer granted custody, is due to go before its senior leaders in the coming months.