In his pre-Budget speech last week, the Chancellor said that students could be offered reduced tuition fees if they volunteered.
But Justin Davis-Smith, deputy chief executive of Volunteering England, argued such a scheme could not be called volunteering. "Volunteering should be undertaken of one's own free will, and it's important that it remains distinctive from paid work," he said.
"The status of volunteers is already unclear in law, and if someone was able to prove they were getting something back from volunteering, they could have the same rights as a paid worker."
A Treasury spokeswoman said: "The proposed fee reduction is not a payment, but an incentive to make it easier for more people to volunteer."
- See Politics special, pages 4 and 5.