Volunteering England is to open an inquiry into the rights of volunteers next month.
The inquiry is being held in response to recent concerns about unpaid workers having no legal rights, which means they can be dismissed without a hearing or appeal.
"It is time to take a considered look at a range of issues related to the legal status of volunteers," said Mike Locke, director of public affairs at Volunteering England. "We feel we can structure the debate," he added.
Volunteering England is expected to issue a statement setting out the full scope of the inquiry on 18 November.
Locke said the charity was putting together the terms of reference and the membership of the group that would lead the inquiry. It is believed that several charities with large numbers of volunteers and volunteer representative groups have been invited to take part.
Patrick Daniels, a director at the Association of Volunteer Managers, said he would welcome any clarification of the legal status of volunteers. But he warned that the crucial issue would be enforcing whatever rights were granted.
"We hope that any inquiry into the rights of volunteers looks at how these rights can be both enforced by the relevant authorities and encouraged through better volunteer management," he said.
Is Szoneberg, director of full-time volunteering at CSV, warned that the inquiry should not create more red tape by focusing too narrowly on legal status. She said this could create "barriers to people giving their time".
She said it was vital that volunteers were treated fairly, but that legal status "should not govern the extent of volunteers' roles and responsibilities like it does with employees".
Udeni Salmon, head of volunteering support at Leonard Cheshire Disability, which has 3,000 volunteers, said: "Under the law, volunteers are not protected in the same way as our salaried staff regarding gender, ethnic and religious discrimination."