Labour said the volunteering idea was a “re-announcement” from 2008.
Under the Conservatives’ volunteering plans, a new law would be passed requiring public sector employers and companies with more than 250 employees to give staff up to three days a year to do voluntary work.
Employers would cover the cost.
Communities Secretary Eric Pickles said the move would “enhance productivity” but suggested that employers worried about the impact it would have on their operations may be able to opt out.
“Nobody is forcing anyone to volunteer. Nobody is forcing companies to organise this volunteering if it causes problems to the company,” he told BBC Radio 4’s Today programme.
“We expect people to have a bit of give-and-take on this as we expect people to have a bit of give-and-take with regard to annual leave.”
He rejected suggestions it could prove a financial burden for smaller firms and a logistical headache for organisations such as the NHS which would have to fill in behind those taking time off.
“It would be worked out according to patterns of work and to ensure it did not cause inconvenience to the health service,” he said.