Urgent action is needed to address a "shocking" decline in the range of services available to young people in London, an assembly member has warned.
An inquiry into the capital's youth services found 81 youth clubs and council youth projects have closed their doors since 2011.
A report shows that at least £39m has also been cut from council youth services over the last seven years.
Sian Berry said youth services had seen devastating cuts for "too long".
Ms Berry, who published the report on Tuesday, described the results as "shocking".
"I hope this is the lowest point London's youth services ever reach and that real investment is put back in from now on", she said.
New Horizon Youth Centre is one London youth service affected by the cuts.
Its CEO, Shelagh O'Connor, said: "Many of the young people we see would not have ended up homeless or would not be involved in youth offending if they were able to access youth clubs and support from experienced youth workers at an earlier stage".
Andreas Koumi, from youth charity Exposure said cuts to its funding has "completely transformed" the way it operates.
"We are now only able to open the Exposure office to young people one day a week, instead of five.
"We have had to disappoint dozens of schools and colleges across London, who would otherwise be sending their students to us on creative learning and work placements."
Across 22 councils, 800 youth service full-time posts have been removed, the report shows.
There has also been a 44% youth service budget cut since 2011, with the average council taking £1.5m out of youth services over this time.
A further £1.2m is due to be cut from 15 councils in 2018/19 budgets.
The Mayor of London, Sadiq Khan, recently set up a £45m 'Young Londoners Fund' which will support education, sport and cultural activities for disadvantaged people.
"While I'm glad the Mayor has committed some desperately needed money to young people it can't all be spent on crime-related issues", Ms Berry said.
"It should be used positively to build up young people, help them flourish and develop skills they will need for life."