Scottish councils are thinking of amending their contracts with social care charities because of a change in vetting procedures by Disclosure Scotland.
Many charities are in the habit of obtaining enchanced checks on all their volunteers, no matter what kind of work they do. They say this is usually a requirement in their contracts with local councils or health services.
But Disclosure Scotland, which provides the checks, has started to refuse to do enchanced checks for those volunteers who do not work with children or vulnerable adults.
The change has been prompted by the Scottish Government, which says those not working with children or vulnerable adults should have only basic checks, which reveal criminal convictions but not other information, such as police intelligence.
A spokesman for the Scottish Government said: "Employers tend to opt for the highest possible level of check. In some cases, volunteers who required only basic checks were being checked to enhanced level. This is not in line with the law."
Rory Mair, chief executive of the Convention of Scottish Local Authorities, which represents local government in Scotland, said he would raise the issue at a meeting with the Society of Local Authority Chief Executives and Senior Managers on 24 April and expected them to change their agreements with charities to reflect the new system.
"Voluntary sector providers are stuck between a rock and a hard place," he said. "We can't leave them caught in this way, so we will have to alter the system."
Until then, he said, it was important to reassure charities and councils that allowing only basic checks would not compromise the safety of their beneficiaries.
Volunteering organisation WRVS Scotland is among a number of charities that have been urging the Scottish Government to come up with a solution.
A spokesman for the organisation said: "This is having an adverse effect on our service provision. Our contracts require us to carry out enhanced checks on volunteers, but the Government won't let us do so.
"Either the Government will have to back down and let us run the checks, or our contractual partners will have to remove the requirement for them."