The most disadvantaged unemployed 16 and 17-year-olds are being "ignored", with chances of learning new skills to help them find work "rapidly declining", a leading charity has said.
Barnardo's argued that the Government's reforms aimed at tackling worklessness and benefit dependency prioritised young people from the age of 18.
The Government was urged to consider alternative education, employment and training options, including programmes targeted at young people living in areas of deprivation, training and qualifications that lead to jobs in specific trades, and guidance and advice to develop employability of young people.
Barnardo's chief executive Anne Marie Carrie said: "Britain's uneven playing field is causing an entire generation of the most disadvantaged teenagers to become 'lost in transition'. Proof of this lies in the unemployment rate for 16 and 17-year-olds which has almost doubled over the last decade.
"If the Government is serious about solving the worsening unemployment crisis it must tackle the issue from the root. This is the only way that the rhetoric of social mobility can become a reality for all young people, especially the most disadvantaged 16 and 17-year-olds.
"Plans to raise the age of compulsory participation in schooling are a step in the right direction. However, the lives of 16 and 17-year-olds will only truly be transformed if flexible and relevant options are put in place which fit their needs."
Barnardo's said that for every young person not in education, employment or training there was an average cost of £56,000 to public authorities over their lifetime.
The report was published ahead of new unemployment figures on Wednesday which will show whether the youth jobless total has gone over a million.
A Department for Education spokesman said: "The figures show that the number of 16-18-year-olds not in education, employment or training (NEET)continues to fall - but the number of teenagers who are NEET is still too high. We want every 16 and 17-year-old to achieve which is why we are increasing apprenticeships and transforming vocational qualifications.
"We're raising the participation age to 18 by 2015 - whether that be full-time education in a school or college, an apprenticeship or full-time work or volunteering with part-time training alongside it. "