Greater London Volunteering, the umbrella body for volunteer centres in the capital, will encourage its members to start charging more money for some of their services so they can use the funds to support their core functions.
The organisation has drawn up a list of services for which it believes volunteer centres could charge more, including brokering employee volunteering projects and advising companies and public sector bodies on volunteer management.
It will consult its members about the list this week and might add more services to it.
Kerry Tweed, director of GLV, said: "Volunteer centres are facing a crisis as the number of applicants for placements is increasing but funding from local authorities is being cut.
"We have to get tougher about our charges. It would be fine to offer services at cost price or for free if we were properly funded - but we're not."