Vulnerable children must have equal access to 'voice'
Vulnerable children do not realise they are entitled to an independent "voice" to represent them, a report claims.
It says many young people are unaware a professional advocate is available through their local authority.
The report says there is a lack of strategic leadership from the Welsh government to ensure children have equal access to the service.
But a government spokesman said it was committed to children and "driving forward" their rights.
Over seven months 500 children and young people across Wales were spoken to.
The report, called Missing Voices, was the commissioner Keith Towler's first statutory review and looked at independent professional advocacy for looked after children and young people; care leavers and children in need.
Mr Towler said he was saddened by the findings.
"The purpose of my review is not to point the finger of blame at anyone but instead to reinvigorate national and local partners to get Wales back on track so that no child is denied access to a professional advocate," he said.
He made 29 recommendations, suggested fundamental changes to national structures and stressed the importance of ensuring all children had equal access to these representatives.
Mr Towler said: "I should not be hearing of episodes where children had been denied access to an advocate and that assumptions had been made they would not benefit from a professional advocate as they were too young.
"During the course of this review we have heard of excellent practice but these pockets of good practice must now become the norm across Wales."
The review's key findings included a lack of clarity and consistency about the way services are commissioned; a lack of strategic leadership by the Welsh government to make sure eligible children and young people have equal access; and there was no annual or systematic monitoring inspection or regulation of the service.
A Welsh government spokesman said it had issued "clear guidance" for local authorities on providing independent, effective and accessible advocacy services.
"We are one of only a handful of countries to have embedded children's rights into our domestic law. Advocacy sits firmly within children's rights as a way for children and young people to be heard when they want someone on their side, someone to help them be safe, to participate and to have access to provisions."
By law, every local authority must provide an independent professional "voice", also known as an advocate, for every looked after child and young person, care leaver and child in need.
They should have access to one when decisions are being made about them or if they want to make a complaint.
Children's charity Tros Gynnal Plant welcomed the report.
"We feel that it gets to grips with many of the issues that we have experienced over the past 10 years," executive director Roger Bishop said.
"We strongly believe that if the recommendations of this report are implemented it would change the life chances for many of our children and young people."