Up to 66 unemployed people are chasing every retail job, with vacancies often closed to young candidates within hours of being advertised, according to new research.
A study by the Joseph Rowntree Foundation (JRF) also found that two-thirds of those applying for jobs did not receive any responses.
A separate report by the TUC found that young black men have experienced the sharpest rise in unemployment since the coalition came to power, with more than one in four of all black 16 to 24-year-olds currently out of work.
JRF researchers sent 2,000 job applications from fictional candidates, with at least five good GCSEs and relevant work experience, to more than 650 vacancies for sales assistants, cleaners, office administrators and kitchen staff.
There were between 24 and 66 unemployed people for every retail vacancy, depending on the supply of jobs in different areas. Vacancies were closed to candidates within days, and in some cases, hours. The study found that only one in four of the vacancies studied offered full-time, day-time work.
JRF spokesman Chris Goulden said: "It's important we have measures that provide more full-time, decent-paying jobs that can ensure work pays. A lack of success in the jobs market saps confidence, demotivates and leaves a scar across a generation of young people, while part-time, low-pay work traps people in poverty.
"On the day the latest unemployment statistics are released, this report makes for grim reading for young people. The intense competition shows the main problem is more fundamental - a major shortage of jobs."
The TUC report said young black men are more likely to be unemployed than any other ethnic group, although young Asian women have been hit by the biggest rise in unemployment over the past decade, up from 6% to 13%.
General secretary Brendan Barber said: "The UK is in the midst of a youth jobs crisis. Over a million youngsters are out of work and many more are struggling to find the finances needed to further their education.
"Last week the Prime Minister singled out employment as a great success of the government. That's cold comfort to the one in four young black men struggling for work, or the one in six jobless young black women."