Almost a third of all jobseeker's allowance claimants are aged between 18 and 24 after a big increase in recent months, according to new research today.
A study of official data by charity Barnardo's showed the number of JSA claimants in the age group jumped by almost 40,000 to more than 408,000 between last November and February.
The charity said the figures, covering England, Scotland and Wales, revealed a "ticking time-bomb" of a "lost generation" of young people.
Across all regions, 18 to 24-year-olds now make up around 30% of all claimants, said Barnardo's.
Scotland saw the biggest increase in claimants in this age group with a jump of 5,200, followed by the North West (4,570), the South East (4,020), Yorkshire & the Humber (3,880) and the West Midlands (3,740).
Barnardo's chief executive Anne Marie Carrie said: "Today's bleak statistics confirm what we already suspected - that high numbers of young people in areas like London and the North East are severely affected by worklessness and poverty which continue to dominate life chances.
"Barnardo's works with the most vulnerable 16 and 17-year-olds and we know that they are struggling to get access to alternatives to mainstream education, apprenticeships or training, all vital to equip them with the skills and confidence to enter the toughest labour market since the 1980s.
"We risk losing an entire generation to long-term cycles of unemployment and a stagnant society if concerted action by Government, local authorities and employers to tackle lack of jobs in the worst hit areas is not taken."