Lord McNally said that many of the successes of the youth justice system - such as falling numbers of first-time entrants and numbers of young people in custody, would likely not have been achieved without the leadership of YOTs and the YJB.
"I often hear from those with long experience of young offenders that it would be an act of vandalism to return to a pre-1998 regime which would allow youth justice services to be gradually sucked back in to general social and welfare provisions, with the resultant loss of focus and specialism," McNally said.
"The hard truth is that we all have to be smarter and more flexible in how we manage our funding.
"But there is already ample evidence that the 1998 act, far from being the straitjacket complained of by some, is a flexible piece of legislation, which allows ample room for initiative and innovation in how services are structured and delivered without losing the statutory underpinning which has made the difference over the last 16 years."
McNally said that before 1998 the core problem of youth justice was that while it was the responsibility of many government departments, it was the priority of none.
"The YJB has provided that priority and leadership at both national and local level," he said.
"What is more, it has been both the example and the pathfinder in championing holistic, interdisciplinary solutions to the problems presented by young offenders and those on the cusp of offending.
"Since 2010 the YJB has seen a cut of nearly two thirds in its budget. It has been able to absorb such draconian cuts because that period has seen a dramatic fall in the number of young people entering the criminal justice system and a similar fall in the number held in custody.
"The fact that today we have a little more than 23,000 new entrants in to the system and less than 900 in custody, compared with 80,000-plus new entrants and 3,500 in custody a decade ago, is evidence-based proof of the effectiveness of the YJB approach."