Forcing school leavers to do three or four months of community service could help bring people together, Tory leader David Cameron has said.
David Cameron says he will be talking to groups about the scheme
Mr Cameron is making the case for his National School Leavers' programme in a speech to voluntary group leaders.
He will say his "instinct" is for the scheme to be compulsory.
He did not want to bring National Service back but he wanted young people to have the same feeling of achieving "something we all did together".
This could help bring people of different races, cultures and backgrounds together, said Mr Cameron.
He said: "If it isn't compulsory or if it isn't universal it could tend to be something else that well-off families do because it's good for their kids but it would not actually reach some of the most marginalised families and excluded children who actually would really benefit."
The community service schemes should not be "dull and worthy" and could range from building hospitals in Rwanda to helping with social services in Stepney, Mr Cameron said.
Full details of the scheme had to yet to be decided, including health and safety issues or what would happen for people who believed they needed to start earning money immediately after leaving school.
Mr Cameron will discuss the idea when he meets youth and voluntary group leaders at the London studios of YCTV, a charity which helps disadvantaged youngsters gain television production skills.
Chancellor Gordon Brown unveiled the government's own National Community Service scheme a year ago to encourage one million young people into volunteering.