Critics say Lord Cullen's recommendations, subsequently accepted by ministers, will fail to stop paedophiles, severely restrict youth work and be an enormous burden at a time when community education budgets are being hammered.
Revised plans for accreditation and vetting, just issued in a consultation document, rehearse the arguments for tighter regulation of an estimated 11,000 clubs and organisations and suggest three models for a scrutinising agency.
But George Johnston, chief executive of YouthLink Scotland, the umbrella organisation for voluntary youth work, said: "We have 100,000 volunteers in youth work and we are trying to stop a handful getting in, knowing it will not succeed anyway.
"The hard reality is that whatever we set up, is it going to affect the situation on the ground one iota? It could make recruiting for youth work a lot more difficult when there are so many hoops to go through in a country that has a great tradition of volunteering."
Mr Johnston said the emphasis should be on raising the quality of training and selection procedures for youth leaders and on ensuring that parents had the appropriate information. Controls would not be voluntary, as ministers maintained, since leaders could not hire a centre unless they were accredited. Insurance companies, which covered activities for clubs, were certain to insist on it.
Among the unanswered questions, Mr Johnston said, was whether 15 and 16-year-old leaders would have to be vetted and whether occasional parent helpers would have to pay the proposed charge of #163;8. Mr Johnston believed that it might take up to six months to be vetted and that parents could lose interest.
David Shelmerdine, chief executive of the Scottish Council of the Scout Association, acknowledged that tighter regulation of entry into youth work would be "a useful adjunct to internal procedures for the safety of children". It was a matter of balancing the deterrent effect on volunteering against the enhancement of child safety - "99.9 per cent of adults" working with young people were suitable.
Mr Shelmerdine said each organisation should have its own arrangements for appointing adults to work unsupervised, supplement ed by checks and training. Nationally, the scout association already monitors 50,000 adults a year and would have to find #163;400,000, plus other costs of around #163;100, 000.
He backed the Government's suggestion that a single agency should be responsible for accrediting groups and vetting adults.
Proposals to make an agency self-financing have been criticised by community education interests. Charlie McConnell, chief executive of the Scottish Community Education Council, said there was "some scepticism" that an agency could survive by charging voluntary groups.
Children in Scotland also condemned plans to make accreditation voluntary and to lay the financial burden on voluntary organisations and, ultimately, parents. Child protection could not be "privatised", a spokeswoman said.