The Prince's Trust is to launch a new strategy to help one million young people it has identified as disadvantaged in the country.
Prince Charles founded the trust in 1976 to help young people
It hopes to get millions of pounds invested in schemes, including apprenticeships, for young people who are not in education or employment.
It also wants reform of the benefits system to encourage more young people into work.
The strategy was developed after a year-long consultation.
The UK's "hardest to reach" 14- to 25-year-olds were consulted, including speaking to young people in care, those in prison and the long-term unemployed.
The trust estimates that there are 649,000 16- to 24-year-olds economically inactive and not in full time education.
A further 405,000 unemployed and not in full time education - a total of 16% of the age group.
Measures to help socially-excluded young people start up their own businesses are also needed, it said.
Other proposals include creating incentives for employers to encourage young parents back into the workplace, greater advertising of youth support services
and programmes to enable youngsters to take part in sport and music.
Its report, Reaching the Hardest to Reach, found that two-thirds of unemployed young people thought there was lack of suitable jobs or careers advice in their
Almost half of socially excluded young people thought there was a lack of things for young people to do, the report said.
And a fifth - "the most socially excluded margins of society" - were failing to turn to anyone for help, the study showed.
The report also identified a belief among some young people that a lifestyle
on benefits was preferable to that of their peers still in education.
It found that 92% thought there were significant gaps in basic services in their community.
The trust's director of programmes and policy, Leslie Morphy, said the consultation showed that young people want more opportunities and practical skills to help them into education, employment and training.
"Only by listening to the evolving needs of young people can we prevent more young people from slipping through the net."
Cabinet office minister Douglas Alexander, a keynote speaker at the strategy launch, said: "We have a duty to listen to what young people say about what we can do to
make it easier for them to become engaged, active and full citizens."
The Prince's Trust has helped almost half-a-million young people since it was founded by the Prince of Wales in 1976.