On Thursday July 23 Cardiff Council will debate whether the council has confidence in the Cabinet following the publication of the inspection report for Cardiff's Youth Offending Service by HM Inspectorate of Probation.
The Welsh Liberal Democrat group on Cardiff Council will amend that motion, calling for a full investigation of what went wrong.
Leader Cardiff Liberal Democrat Council Group Cllr Rhys Taylor said:
"One of the things I wanted to do having been elected to Cardiff Council in 2017 was stand up for children and young people in our city. Those who have been let down time after time and forgotten.
"We owe it to those children and young people, their families, and the staff across the service to get under the skin of what happened. It's absolutely vital that we have an open and transparent discussion about how we got to this point and where we go next to understand what needs to happen to rebuild their trust."