Leaders of the national uniformed youth organisations say the proposed scheme, which will cost up to pound;10 for each check, will be an unacceptable financial strain. The bill is put at more than pound;200,000 a year.
Jim Duffy, chief executive of the Scout Association in Scotland, said:
"Child protection and safety is an obligation on the community as a whole. The Scottish parliament must ensure that voluntary youth organisations have free access to SCRO (Scottish Criminal Record Office) checks."
The Scottish Office has admitted that legislation will be needed before full vetting procedures are introduced for voluntary helpers. It could be two years until the system is operational, five years after the Dunblane shootings.
Ministers have reopened talks on how best to establish a "consultancy services index", which will have statutory backing. The index will contain information about criminal convictions and other details about adults who want to work with children.