ALMOST a quarter of young Australians are working insecure, black-market jobs and missing out on their entitlements, trade unions say.
ACTU president Ged Kearney says employers are paying workers cash to avoid legal obligations and taxes.
"The illegal use of cash-in-hand payments to workers is one of the dirty secrets of the Australian economy," she said yesterday.
A survey of more than 1000 workers by the Victorian Trades Hall Council and the ACTU found almost a quarter of people aged between 18 and 30 were being paid cash-in-hand and off the books.
The national survey, conducted earlier in September, found a tenth of Australian workers were working black market jobs.
Between 50 and 60 per cent of those jobs did not pay superannuation, annual leave, sick leave or penalty rates.
Ms Kearney said the rise of insecure work had contributed to the cash culture.
"Workers are increasingly doing jobs that have irregular and inconvenient hours, have limited entitlements and have no job security," she said.
"Cash-in-hand workers is just part of this trend, which makes it tougher for workers."
Younger workers were more likely to work cash-in-hand jobs than older workers.
"There is a real concern young workers are being told they must work cash-in-hand in one of their current jobs," Ms Kearney said.